Zoom lens system

ABSTRACT

A zoom lens system is disclosed. The zoom lens system forms a final image of an object and a first intermediate real image between the object and the final image. The zoom lens system includes a first optical unit located between the object and the first intermediate real image. The first optical unit comprises at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image. The zoom lens system also includes a second optical unit located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image. The zoom lens system provides a wide zoom range of focal lengths with continuous zooming between the focal lengths.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-In-Part (CIP) application of U.S.patent application Ser. No. 10/622,914, filed Jul. 18, 2003 now U.S.Pat. No. 6,961,188, which claims the benefit of U.S. ProvisionalApplication No. 60/397,882, filed Jul. 22, 2002, which application isspecifically incorporated herein, in its entirety, by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to optical lens systems for cameras and otheroptical devices, and, in particular, to high performance zoom lenssystems that produce a high quality image over a full zoom range offocal lengths and are capable of being provided with an extremely largezoom ratio.

2. Description of Related Art

General Background of the Invention. The use of zoom lens systems forall types of photography, such as broadcast television, high definitiontelevision (“HDTV”), advanced television (“ATV”), video camcorders, filmcinematography and still photography has become increasingly popular. Asthe use of zoom lens systems has increased, the demand for wider rangesof zooming capability, i.e. large zoom ratios, has also increased. Forexample, the zoom lens systems used in broadcast television havesteadily increased in zoom ratio capability over the years to a maximumof about 101 to 1 at present but there is a demand for a still largerzoom ratio. While the focal length range of a conventional zoom lenssystem may be increased by the use of a drop-in extender or othermultiplier, such as a broadcast television zoom lens system with a focallength range of 8.9 mm to 900 mm being increased to 17.8 mm to 1800 mmto increase the telephoto capability, this does not change the zoomratio of about 101 to 1. Moreover, for broadcast television zoom lenssystems there are somewhat different requirements for “studio” (indoor)or “outside broadcast” (outdoor) use concerning the focal length rangeand acceptable “f” numbers, whereby it has become conventional practiceto employ two different zoom lens systems for indoor and outdoorbroadcast television uses to maximize the capabilities for both types ofuses.

Further, in addition to the demand and desirability of using zoom lenssystems with wider ranges of focal lengths, such lenses must retainsuperior optical characteristics and performance that previously hasbeen accomplished only by using separate objective lenses of differentfixed focal lengths or zoom lens systems with a limited zoom ratio. Asthe zoom ratio increases, the difficulty in providing a high performanceoptical system with superior characteristics and performance alsoincreases. Even most previously available zoom lens systems of a limitedzoom range have one or more undesirable limitations such as theinability to focus adequately over the entire focal length range, theinability to focus on close objects, the lack of adequate opticalperformance over the entire focal length range and focus distance, thecost, the large size for the limited zoom range achieved and the like.

Still further, as the zoom range of a lens system increases, generallythe length and weight increases whereby the difficulty in maintainingthe lens and camera steady also increases. Therefore image stabilizationalso becomes an issue for the design of a practical zoom lens systemhaving a large focal length range and zoom ratio.

Moreover, as the focal length range of a zoom lens system increases,generally the focusing problems also increase. Although close focusingat long focal lengths of the zoom range is not absolutely necessary, itis required at lesser focal lengths. In the past, continuous focusingover a considerable conjugate range from infinity to objects at a veryshort distance such as about 8 feet or less has been difficult toachieve. Further, the problem of “breathing” of the final image (wherethe perceived size changes as the focus distance is changed) at shorterfocal lengths must be minimized to avoid, for example, one persondisappearing from the scene as the focus is changed to another person ata different distance from the lens. These focus performancerequirements, including maintaining the quality of the final image, tendto increase substantially the weight and cost of the zoom lens systemunless the size can be minimized and performance maximized by theoverall lens design, including glass selection.

Background Information Concerning Zooming. As discussed above, zoom lenssystems with a wide-range of focal lengths are very desirable innumerous photographic applications, including broadcast television,cinematography and video and still photography. One standard zoom lenssystem used in these applications has a four-group PN(P or N)Pstructure, where P stands for a group of at least one lens elementwherein the lens group has positive power, N stands for a group of atleast one lens element wherein the lens group has negative power, andthe groups are identified consecutively from the object space toward theimage space, as is conventional. The front positive group is oftencalled the focusing group because it can be moved for focusing the zoomlens system at any focal length position without the need to refocus forany other focal length of the zoom lens. The second negative group isthe variator, and it induces significant magnification change duringzooming. The third group, which can in general have either positive ornegative power, is the compensator, and it is movable to insure that theimage plane remains stationary. It also can provide some of themagnification change to effect zooming. The final positive fourth groupis often called the prime lens group because it forms a sharp image.

This basic zoom lens system is suitable for zoom ratios of 50:1 or evenmore. As the zoom ratio is extended to about 100:1, however, thevariator is required to change its object magnification to such anextent during zooming that aberrations become impracticably large anddifficult to correct. In addition, at such large zoom ratios there is avery large change in entrance pupil location during zooming, and thistends to make the front group very large and difficult to correct.Another problem derives from the fact that, to reduce the aberrationchange that results from a large change of magnification, it isdesirable that the variator have reduced optical powers. Weaker opticalpower, however, also increases the lens travel and length of the opticalsystem. For a narrow field-of-view this would not be a problem, but, fora wide field-of-view, large motions lead to an increase in the principalray heights at the rear portion of the lens system. Since therequirements for either the front or the rear of the lens system can besatisfied, but not simultaneously, this results in no ideal place forthe aperture stop. If the stop is placed near the front of the lens, thefront lens element diameters, and resultant aberrations, are reduced,and if the aperture stop is placed nearer to the rear part of the lenssystem, the rear lens diameters and resultant aberrations are decreased.

SUMMARY OF THE INVENTION

General Summary of the Invention. It is an object of the presentinvention to provide a zoom lens system that overcomes the problems andinefficiencies of prior zoom lens systems having large zoom ratios. Afurther object is to provide a zoom lens system with a wide zoom rangeof focal lengths and high performance characteristics for both indoorand outdoor use. A still further object of this invention is to providea zoom lens system with a ratio of about 300 to 1 and a zoom range, forexample, from about 7 mm to 2100 mm focal length, with continuouszooming between the focal lengths. Still another object of thisinvention is to provide a high performance zoom lens system with anoptical system having a front zoom lens group for forming anintermediate image and a rear zoom lens group to magnify that image tothereby produce an extremely large zoom ratio. Still another object isto provide such a zoom lens system with optical image stabilization.Still another object is to provide such a zoom lens system with afocusing lens group capable of precise focusing over the entire focallength range of the zoom ratio.

Although of particular benefit for achieving large zoom ratios, the zoomlens systems of the invention can have conventional zoom ratios, e.g.,zoom ratios associated with such consumer products as video camcorders,still cameras and the like. It is an additional object of the inventionto produce zoom lens systems for these smaller zoom ratio applications.

Other and more detailed objects and advantages of the present inventionwill readily appear to those skilled in the art from the variouspreferred embodiments.

Summary of the Zoom Ratio Aspects of the Invention. The presentinvention overcomes the obstacles that currently limit zoom lens systemsto a zoom ratio of about 101:1. The basic idea of the invention can beviewed as the use of a compound zoom lens system that consists of twoseparate zoom lens portions wherein the front zoom lens portion forms anintermediate image, and the rear zoom lens portion is a relay thattransfers the intermediate image formed by the front zoom lens portionto the final image. The total zoom ratio of the complete compound zoomlens system is equal to the zoom ratio of the front zoom lens multipliedby the zoom ratio of the relay. Thus, if the zoom ratio of the frontzoom lens portion is 20:1 and the zoom ratio of the relay is 15:1, thenthe zoom ratio of the entire compound zoom lens system is 300:1. Thepresent invention can be used to achieve a zoom ratio of 300:1 or more,which greatly exceeds the practical limit of conventional zoom lenssystems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-5 are optical diagrams of compound zoom lens systems of thepresent invention for describing some of the principles and variationsin the moving and fixed units employed in the system and some of thepossible embodiments of the invention, with FIGS. 1-3 illustrating asystem having about a 300:1 zoom ratio, FIGS. 4A and 4B having about a130:1 zoom ratio and FIGS. 5A and 5B having about a 13:1 zoom ratio inan ultra wide angle lens system;

FIGS. 6A and 6B are optical diagrams of another embodiment of the zoomlens system of the present invention using three moving zoom lensgroups, with the three zoom groups positioned for a short focal lengthin FIG. 6A and for a long focal length in FIG. 6B;

FIGS. 7A and 7B are optical diagrams of another embodiment of the zoomlens system of the present invention using four moving zoom lens groups,with the four zoom groups positioned for a short focal length in FIG. 7Aand for a long focal length in FIG. 7B;

FIGS. 8A and 8B are optical diagrams of another embodiment of the zoomlens system of the present invention using four moving zoom lens groups,with the four zoom groups positioned for a short focal length in FIG. 8Aand for a long focal length in FIG. 8B;

FIGS. 9A and 9B are optical diagrams of another embodiment of the zoomlens system of the present invention using three moving zoom lensgroups, with the three zoom groups positioned for a short focal lengthin FIG. 9A and for a long focal length in FIG. 9B;

FIGS. 10-62 are figures that all relate to a single embodiment of thezoom lens system of the present invention that has a zoom ratio of about300:1, with FIG. 10 being an optical diagram of the entire lens system,FIGS. 11-30 comprising optical diagrams of the lens system in 20different representative positions of the movable lens elements, FIGS.31-34 comprising optical diagrams of only the lens elements of the focusunit in four of the representative positions, FIGS. 35 and 36illustrating only the front two zoom lens groups in two of therepresentative positions, FIGS. 37 and 38 illustrating only the rearzoom lens group in two of the representative positions, FIGS. 39-58comprising ray aberration diagrams for the same 20 representativepositions of all of the lens elements illustrated in FIGS. 11-30,respectively, FIG. 59 comprising a graph of the focus cam movementrelative to the focus distances from minimum (bottom) to infinity (top),FIG. 60 comprising graphs of the three zoom cam movements relative tothe system focal lengths, FIG. 61 comprising a graph of the “f” numbersof the system at the final image relative to the system focal lengths,and FIG. 62 comprising a graph of the stop diameters relative to thesystem focal lengths;

FIGS. 63 and 64 are an optical diagram and ray aberration graphs,respectively, for another embodiment of the zoom lens system of thisinvention incorporating a binary (diffractive) surface;

FIGS. 65 and 66 are an optical diagram and ray aberration graphs,respectively, for still another embodiment of the zoom lens system ofthis invention incorporating a binary (diffractive) surface; and

FIGS. 67-70 are figures that relate to a still further embodiment of theinvention having a zoom ratio of about 400:1 with FIGS. 67 and 68 beingoptical diagrams at focal lengths of 7.47 mm and 2983 mm, respectively,and FIGS. 69 and 70 being ray aberration graphs at focal lengths of 7.47mm and 2983 mm, respectively;

FIGS. 71 and 72A-72D are optical diagrams for an example of stillanother embodiment of the zoom lens system of this inventionincorporating a mirror for folding the lens for added compactness, withFIGS. 72A-72D showing the folded lens in a flat (unfolded) orientationfor clarity, and illustrating various positions of the zoom groups;

FIGS. 73A-73C are optical diagrams for an example of an infrared (IR)embodiment of the zoom lens system of this invention, illustratingvarious positions of the zoom groups; and

FIGS. 74-76 are ray aberration graphs corresponding to the position ofthe zoom groups shown in FIGS. 73A-73C, respectively;

FIG. 77 illustrates an unfolded layout of a second example of an IRembodiment of the zoom lens system of this invention, with lens elementsand surfaces identified;

FIGS. 78A-78F illustrate an unfolded layout of the second example IRembodiment at Zoom Positions Z1-Z6; and

FIGS. 79A-79F illustrate the diffraction modulation transfer function(MTF) of selected light rays for the second example IR embodiment at thezoom positions shown in FIGS. 78A-78F.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description of preferred embodiments, reference is madeto the accompanying drawings, which form a part hereof, and in which isshown by way of illustration specific embodiments in which the inventionmay be practiced. It is to be understood that other embodiments may beutilized and structural changes may be made without departing from thescope of the preferred embodiments of the present invention.

In accordance with its general aspects, the invention provides a zoomlens system for forming a final image of an object, said system forminga first intermediate real image between the object and the final image,said system comprising:

(a) a first optical unit (e.g., lens elements 8 through 15 in FIG. 10)located between the object and the first intermediate real image, saidunit comprising at least one optical subunit which is moved to changethe size (magnification) of the first intermediate real image (e.g.,lens elements 8 through 11 are the primary source of magnificationchange for the first optical unit in FIG. 10); and

(b) a second optical unit (e.g., lens elements 26 through 33 in FIG. 10)located between the first intermediate real image and the final image atleast a portion of which (e.g., one or more optical subunits or theentire second optical unit) is moved to change the size (magnification)of the final image (e.g., in FIG. 10, lens elements 26 through 28 of thesecond optical unit are moved to change the size of the final image).

Preferably, the zoom lens system includes one or more optical subunitsin either or both of the first and second optical units which is movedto hold the axial position of the final image substantially stationaryas the focal length of the system is changed (e.g., lens elements 12through 15 are the primary source of this function in FIG. 10). Such asubunit, however, may not be needed in all cases, e.g., if the overalloptical system has an axially movable sensor.

Preferably, in addition to the first and second optical units, the zoomlens system comprises a focus unit (e.g., lens elements 1 through 7 inFIG. 10), a pupil imaging unit (e.g., lens elements 16 through 25 inFIG. 10), and/or an image stabilization unit (e.g., lens elements 34through 39 in FIG. 10).

Preferably, the focus unit is (1) positioned in front of the firstoptical unit, (2) comprises two optical subunits that are movable alongthe zoom lens system's optical axis (e.g., lens element 2 and elements 3and 4 in FIG. 10), and/or (3) comprises seven or less lens elements.

Preferably, the image stabilization unit comprises (1) at least one lenselement that is laterally movable off the system's optical axis (e.g.,lens elements 34 through 36 in FIG. 10), and/or (2) at least one lenselement that is movable along the optical axis (e.g., lens elements 37through 39 in FIG. 10). The light passing through the system ispreferably substantially collimated between said laterally and axiallymovable lens elements of the image stabilization unit.

In addition to the first intermediate real image, the zoom lens systemsof the invention can form additional intermediate real images betweenthe object and the final image. The systems can include additionaloptical units besides the first and second units for changing the sizes(magnifications) of those additional intermediate real images.

Preferably, the first intermediate real image is formed in an air spacebetween the optical elements of the zoom lens system (e.g., the lenselements, prisms, folding mirrors or the like used in the system) anddoes not pass through any surface of an optical element during zooming.When more than one intermediate real image is formed, this is alsopreferably true for all of the intermediate images.

The first optical unit in combination with other units of the system canhave the form of a conventional zoom lens. Similarly, the second opticalunit in combination with other units of the system can have aconventional zoom lens form. The overall system can thus be viewed as a“compounding” of two conventional zoom lenses with, in accordance withthe invention, control of pupil imaging between the compounded zoomlenses.

The overall system can also be viewed as a front zoom lens which formsan intermediate image and a relay system which receives the intermediateimage and changes its magnification to form the final image.

These approaches for describing the zoom lens systems of the inventionare used herein in the detailed discussions of various aspects of theinvention. Although these approaches provide a convenient way ofdescribing the invention, it is to be understood that the invention isnot limited to these descriptions and various embodiments andapplications of the invention may not be completely amenable to suchdescriptions.

In accordance with other aspects, the invention provides a zoom lenssystem for forming a final image of an object, said system having arange of focal lengths between a maximum focal length and a minimumfocal length and forming at least a first intermediate real imagebetween the object and the final image for all focal lengths within saidrange, said system comprising:

(a) a first lens unit having a focal length that is changed to changethe size (magnification) of the first intermediate real image, saidfirst lens unit being located between the object and the firstintermediate real image for all focal lengths within said range; and

(b) a second lens unit for changing the size (magnification) of thefinal image, said second lens unit being located between the firstintermediate real image and the final image for all focal lengths withinsaid range.

In accordance with additional aspects, the invention provides a zoomlens system which comprises a variable focal length front lens unitwhich forms an intermediate real image and a variable magnification rearlens unit which forms an image (preferably, a real image) of theintermediate image.

In accordance with further aspects, the invention provides a compoundzoom lens system that collects radiation from an object space anddelivers the radiation to a final image in image space, said systemcomprising multiple zoom lens portions including a first zoom lensportion forming an intermediate image of the radiation from the objectspace and a last zoom lens portion forming the final image in the imagespace.

In accordance with still further aspects, the invention provides a zoomlens system for forming a final image of an object, said system havingan optical axis, a front lens surface, an aperture stop, and a chief raywhich crosses the optical axis at the aperture stop, said systemcomprising first and second lens units that are moved to change thefocal length of the system, wherein:

(a) between the front lens surface and the final image, the chief raycrosses the optical axis at at least one other location besides saidaperture stop for all focal lengths of the system; and

(b) the system forms an intermediate real image that is located betweenthe first and second lens units for all focal lengths of the system.

Description of Some Zooming Principles and Systems of the Invention.There are some unique aspects to a compound zoom lens system (i.e., afront zoom/zoom relay system) that enables an extraordinarily highdegree of optical correction to be achieved. Imagine for a moment asimplified scenario in which the complete zooming motion takes place instages. In the first stage the relay is initially set at a short focallength position that provides a small magnification of the intermediateimage. The object conjugate of the relay will then have a smallnumerical aperture NA and its image conjugate will have a largenumerical aperture NA. (As conventionally defined, the numericalaperture “NA” is equal to the sine of the vertex angle of the largestcone of meridional rays that can enter or leave an optical system orelement, multiplied by the refractive index of the medium in which thevertex of the cone is located; and in the lens system opticalprescriptions set forth below the “f” number equals the inverse of twiceNA, i.e. f=1/2×NA). Since the NA in object space for the relay is equalto the NA in image space for the front zoom lens portion, then it isclear that in this first stage, the front zoom lens portion need only bewell corrected for a small NA.

In the second stage, the front zoom lens portion is stationary at itslong focal length position, and the relay then zooms to magnify theintermediate image to a greater and greater extent. As the focal lengthof the system increases during this second stage, the image NA of therelay becomes smaller and the object NA of the relay becomes larger.Hence, the image NA of the front zoom lens portion must also becomelarger. However, at the same time, the radial part of the intermediateimage that is actually used becomes smaller and smaller as the systemfocal length gets larger.

Thus, the front zoom lens portion need not be corrected for asimultaneously large intermediate image size and a large relativeaperture (NA). Rather, it needs to be corrected for a large intermediateimage size at a small aperture, and for a small intermediate image sizeat a large aperture. This makes the design of the front zoom lensportion considerably easier than the design of a traditional zoom lenssystem having the same zoom ratio as the front zoom lens system of thepresent invention.

Likewise, the relay need only be corrected for a large image NA andlarge object size at the small magnification end of its focal lengths.At the other end of its zoom range of focal lengths, the object size issmall and the image NA is also small.

As discussed above, in addition to a front zoom lens portion and arelay, the zoom lens systems of the invention preferably also include apupil imaging unit. This unit serves to image the exit pupil of thefront zoom lens portion into the entrance pupil of the relay. Byselecting the appropriate powers, not only can the lens diameters, andattendant aberrations, of the relay be minimized, but control of theexit pupil position of the system can be improved.

As also discussed above, the intermediate image formed by the front zoomlens portion is preferably located at a position where it does not passthrough any lens surfaces as the system is zoomed from its minimum toits maximum focal lengths. By being between the front zoom lens portionand the rear relay, the intermediate image is automatically behind theaxially moving lens unit or units that provide zooming in the front zoomlens portion and in front of any axially moving lens units that providezooming in the rear zoom portion. Since in certain embodiments of theinvention the intermediate image can move during zooming, the locationsfor the lens surfaces on either side of the intermediate image, whetherthose surfaces are fixed or moving, are preferably chosen so thatnotwithstanding the motion of the intermediate image, the surfacesremain spaced from the intermediate image throughout the zoom range ofthe system.

Various of the foregoing features of the invention are illustrated inFIGS. 1-3 for a PNPP-PNPP compound zoom lens system with a zoom ratio ofabout 300:1. As indicated in FIG. 1, this compound zoom lens system hasa front zoom lens portion with a zoom ratio of about 20:1 and a rearzoom lens portion (relay) with a zoom ratio of about 15:1. The groupsand their positive or negative power signs are also indicated in FIG. 1.In this compound zoom lens system, the relay is stationary as the frontzoom lens portion is operated from its shortest focal length position(shown in FIG. 1) to its longest focal length position (shown in FIG.2). Once the front zoom lens portion reaches its long focal lengthposition, the relay begins to vary the magnification of the intermediateimage to further increase the focal length of the compound system. FIG.3 shows the system in its maximum focal length condition, in which thefront zoom lens portion is at its maximum focal length position and therear zoom (relay) lens portion is in its maximum magnification position.

FIGS. 1 and 2 show the small NA at the intermediate image plane andlarge NA at the final image plane that occurs during the initial phaseof zooming from short to long. The size of the intermediate image islarge during this phase, as shown in the figures. FIG. 3 shows that theNA becomes larger at the intermediate image and smaller at the finalimage at the longest focal length position.

Note that in this example there are 8 zoom lens groups, but only 4 ofthem are independently movable for zooming. The 1st, 4th, 5th, and 8thgroups are all stationary with respect to the final image. Duringfocusing, however, one or more of these groups can be made to move.

The scenario sketched out here is for exemplary purposes. In practice,the zooming motion need not be clearly divided into two stages, and as aresult the relay or a part of it can move during the initial zoomingstages and not just near the long end of the focal lengths.

The example of FIGS. 1-3 described above has a PNPP-PNPP construction inwhich the dash “-” signifies the end of the front zoom lens portion.Both the front zoom lens portion and rear zoom lens portion havevariator and compensator zooming groups. One advantage of thisconfiguration is that the intermediate image can be made absolutelystationary if desired. Rendering the image stationary will prevent itfrom passing through any optical surface that might reveal surface flawsand dust images that will appear at the final image. Using a four-groupconstruction in the rear zoom lens portion also permits better controlof the exit pupil position, which may be important for matching thetelecentricity requirements of certain image sensors.

If movement of the intermediate image can be tolerated, then it ispossible to eliminate one of the compensators. Removal of the rearcompensator is preferred in this case because it only moves when thebeam diameters are relatively small. The resulting construction willthen be a PNPP-PNP configuration.

For both of these configurations care must be taken to match the exitpupil of the front zoom lens portion with the entrance pupil of therelay. For this purpose, an eyepiece-like group is beneficial forconverting the diverging beams emanating from the intermediate imageinto approximately parallel beams entering a normal PNP- or PNPP-typezoom lens system corrected for infinite conjugates.

One aspect of high-speed (large aperture) ultra-wide-range of focallengths compound zoom lens systems of this type is that the intermediateimage and all of its image faults are highly magnified by the zoomgroups in the relay at the long focal length position. This placesstringent requirements on the correction of secondary color aberrationsin the front zoom lens portion and especially the focusing group. Inorder to accomplish this correction, it is necessary to use at leastone, and more likely several, fluor-crown glass elements. As analternative, calcium fluoride or binary (diffractive) surfaces couldalso be used for this purpose.

A variety of binary (diffractive) surfaces (diffractive elements) can beused in the practice of the invention. For example, for certainapplications, one or more diffractive optical elements of the typedisclosed in U.S. Pat. No. 6,507,437, assigned to Canon, can be used,either alone or in combination with other approaches for correctingchromatic aberrations.

One big advantage of using a PNPP-PNPP or PNPP-PNP configuration overexisting zoom lens systems is that both the front zoom lens portion andthe rear zoom lens portion (relay) system can have very large zoomratios. It is quite reasonable to have a zoom ratio of 20:1 or more foreither the front zoom lens portion or the rear zoom lens portion in thiscase, so that a total zoom ratio of 400:1 or more is possible. However,if such a large zoom ratio is not required, it is possible to simplifythe system significantly by instead using a relay with an NPconfiguration having two moving groups. Such a relay is very useful forlarge aperture applications with a total zoom ratio in the relay ofabout 3:1 to about 10:1. An example of a compound zoom lens system witha zoom ratio of about 130:1 having an about 20:1 zoom ratio PNPP frontzoom lens portion and an about 6.5:1 zoom ratio relay is shown in FIGS.4A and 4B. FIG. 4A illustrates the minimum focal length of about 7 mmand FIG. 4B illustrates the maximum focal length of about 900 mm. Onedisadvantage of this configuration is that the rearmost lens group isnot stationary; hence it must be designed to withstand a considerablechange of magnification at large apertures, which makes it somewhatdifficult to design.

An even further simplified construction consisting of an NP front zoomlens portion and an NP rear zoom lens portion (relay) can also bedesigned, although the maximum zoom ratio in this case will be lowered.Clearly, the technique can be generalized to include a large number ofcombinations of various zoom lens arrangements for the front zoom lensportion and for the rear zoom lens portion. For example, a high zoomratio, ultra wide angle zoom lens system can be constructed by using anNP, NPP or NPNP ultra wide angle front zoom lens portion having a zoomratio of about 2:1 with an NP rear zoom lens portion (relay) having azoom ratio of about 6.5:1. The result would be a compound zoom lenssystem with a zoom ratio of about 13:1 with a maximum full field of viewof up to 100 degrees or more. FIGS. 5A and 5B illustrate a 4.4 mm-57.2mm, f/3-f/7 compound zoom lens system with a zoom ratio of about 13:1for a ⅔″ sensor. The full-field angle at the wide-angle end of thiscompound zoom lens system is more than 102 degrees. Clearly, a PNPP-typerear zoom lens portion (relay) similar to the one used in FIGS. 1-3could be used with this same ultra wide angle front zoom lens portion toyield an ultra wide angle compound zoom lens system with a zoom ratio ofabout 30:1.

The existence of an intermediate image is common to all of theseconfigurations, and this offers some unique opportunities for aberrationcorrection that are not typically available in zoom lens system types ofthe prior art. For example, aspheric surfaces placed on elements locatednear the intermediate image can have a strong impact on distortion andother field aberrations without disturbing the spherical aberrationcorrection. Advantages of placing an aspheric surface in this areainclude that the tolerances are generous because the beam diameters aresmall, and the elements themselves are small. This means that the costof using aspheric surfaces in this region is minimal.

Detailed Description of the Preferred Embodiments. As described above inthe section entitled “Description of Some Zooming Principles and Systemsof the Invention”, each of the herein disclosed embodiments of thepresent invention includes a front zoom lens portion and a rear zoomlens portion thereby forming a compound zoom lens system. Anintermediate image is formed after the front zoom lens portion wherebythe rear zoom lens portion functions as a zoom relay to magnify theintermediate image so as to produce the magnified final image forcapturing by film or any other kind of light detector or capture device,such as a charge coupled device (CCD), in a camera. For purposes of thisapplication, the term “camera” is used generically to describe any kindof light detecting or capturing device that may be placed after the lenssystem of the present invention, including a still, video or moviecapture device, whether containing film, videotape, optical disk, CMOS,CCD or another storage medium, or an eyepiece or the human eye. Any such“camera” may include additional lens elements. At present it iscontemplated that the front zoom lens portion will be comprised of twomoving zoom lens groups and the rear zoom lens portion will be comprisedof either one or two moving zoom lens groups, but it is to be understoodthat more or fewer moving zoom lens groups may be used without departingfrom the present invention. Also, at present it is contemplated thatonly one intermediate image will be formed in the entire compound zoomlens system but other embodiments of the present invention may form morethan one intermediate image.

In addition to the front and rear zoom lens portions, the compound zoomlens system of the present invention preferably includes a focus lensgroup. It is preferred that the focus lens group be positioned at thefront of the lens system, as shown by each of the embodiments disclosedherein, although it is possible to accomplish some and maybe all of thefocusing elsewhere in the compound zoom lens system in other embodimentsof the invention.

When a single intermediate image is formed in this compound zoom lenssystem, the final image is upside down and reversed left-to-right fromthe conventional orientation produced by an objective lens and thereforethe image orientation must be accommodated by the camera. For a videocamera using a single chip for the detector, it is possible to merelyrotate the chip 180 degrees about the optical axis so that the chipreads the final image as though it is conventionally oriented. Anothersolution to the orientation problem for a video camera is to reverse theorder in which the data is scanned, i.e. instead of from left-to-rightand top-to-bottom the data can be read right-to-left and bottom-to-topto achieve the conventional orientation. Still another solution to theorientation problem for a video camera that uses a “frame store” featureto store an entire frame on a memory chip before it is transmitted foruse is to merely transmit the stored frame from the frame store memoryin the reverse order. For a movie film camera, the entire camera withthe film magazine may be turned upside down to, as a result, run thefilm upwardly for correcting the image orientation. Another solution forthe orientation of the image in a movie film camera used in theconventional manner and employing the present zoom lens system is to usedigital compositing wherein the film is digitally scanned and then, forexample, after digital manipulation the image is imposed on new film inthe conventional orientation. The use of a prism in or in connectionwith the lens system of this invention will also correct the orientationof the final image. For this approach, care must be taken so that theprism will not cause excessive deterioration of the quality of the finalimage, especially for high performance applications of the present lenssystem.

Due to the compound zoom arrangement of the zoom lens system of thepresent invention, the body of the compound lens system will often be ofsubstantial length and therefore any deflection or vibration of the lenssystem relative to the camera may cause unacceptable deflection orvibration of the final image in the camera. Thus, at least for compoundzoom lens systems of the present invention having large zoom ratios,long focal lengths and/or substantial length, it is contemplated that animage stabilization arrangement will be employed. While electronic imagestabilization may be appropriate for some video camera applications, forhigher performance zoom lens system applications it is preferred that anoptical image stabilization arrangement be included in the body of thecompound zoom lens system and preferably near the camera end of the lenssystem, such as is included in the embodiment of FIGS. 10-62 describedbelow.

Although it is more desirable to design and construct the compound zoomlens system of this invention as an integral unit for maximumperformance, it is also possible to use two or more separable componentsto achieve the basic features. For example, a conventional zoom lens ora modified form thereof may be used as the front zoom lens portion andthen the rear zoom lens portion may be comprised of a separateattachment that relays and varies the magnification of (e.g. zooms) theimage formed by the front zoom lens portion, which image becomes the“intermediate” image, to form the final image. Thus, the front zoom lensportion will provide one zoom ratio and the rear attachment zoom portionwill provide another zoom ratio. However, for such a combination, thepupil imaging should be controlled to obtain a final image of acceptableoptical quality. Other such combinations of conventional and/or modifiedlens portions may also be used to provide the compound zoom lens systemof the present invention.

FIGS. 6A through 9B illustrate optical diagrams for four differentembodiments of the zoom lens system of the present invention. At the farright of each of the FIGS. 6A-9B the two rectangular blocks representthe prism blocks for a conventional 3 CCD ⅔″ detector, which is part ofthe video camera and therefore not part of the zoom lens system.

The following tables list the lens system optical prescriptions, thevariable thickness positions for various surfaces, and the focal lengthsand magnifications for various surface groups for each of those fourembodiments. For simplicity and clarity in view of the large number ofsurfaces and the small scale of the optical diagrams that include all ofthe elements, only some of the surfaces in FIGS. 6A through 9B thatcorrespond to the surfaces set forth in the lens system opticalprescriptions are identified. A more detailed explanation of the tablesis provided following the tables.

TABLES FOR FIGS. 6A & 6B LENS SYSTEM OPTICAL PRESCRIPTION Glass GlassSurface Radius Thickness Index Dispersion OBJECT Infinity Infinity S1925.010 10.000 1.90135 31.5 S2 280.601 20.595 S3 626.503 19.748 1.4969981.6 S4 −2050.828 0.300 S5 −2871.294 12.027 1.49699 81.6 S6 −624.4680.300 S7 266.779 14.079 1.49699 81.6 S8 497.283 0.300 S9 351.230 16.2281.49699 81.6 S10 1246.212 0.300 S11* 185.443 25.083 1.49699 81.6 S12839.856 Variable S13 301.162 5.346 1.77249 49.6 S14* 71.693 15.360 S15−3690.461 2.000 1.77249 49.6 S16 100.162 27.480 S17 −70.544 5.4561.80400 46.6 S18 −3458.086 8.858 1.92286 18.9 S19 −125.683 Variable S20−257.845 12.063 1.49699 81.6 S21 −78.411 0.127 S22 149.706 13.0011.49699 81.6 S23 −98.095 2.000 1.80349 30.4 S24 −266.962 0.100 S25114.669 6.712 1.49699 81.6 S26 485.498 Variable STOP Infinity 24.165S28* −41.960 2.000 1.60311 60.7 S29 40.078 31.156 1.69894 30.1 S3083.406 12.225 S31 −64.844 2.590 1.60311 60.7 S32 912.611 13.001 1.6989430.1 S33 −52.224 24.076 S34 99.845 2.313 1.49699 81.6 S35 167.386 15.000S36 155.608 14.122 1.49699 81.6 S37 −47.886 9.568 1.87399 35.3 S38−67.571 0.018 S39 381.504 2.000 1.87399 35.3 S40 49.653 11.590 1.4387595.0 S41 −583.112 43.970 S42* 50.132 14.235 1.43875 95.0 S43 482.784Variable S44 −23.147 2.000 1.69100 54.8 S45* 32.021 1.889 S46 52.65521.412 1.84666 23.8 S47 −380.467 Variable S48 102.416 11.302 1.4969981.6 S49 −50.958 0.405 S50* 34.098 13.134 1.49699 81.6 S51 43.222 1.521S52 58.738 10.784 1.49699 81.6 S53 −35.052 2.000 1.74319 49.3 S54 43.4221.334 S55 57.389 10.079 1.49699 81.6 S56 −38.685 0.658 S57 −35.272 3.7721.78472 25.7 S58 −56.940 0.500 S59 166.529 4.833 1.69100 54.8 S60−100.192 0.250 S61 83.273 5.608 1.69100 54.8 S62 808.1 Variable S63Infinity 13.200 1.51680 64.1 S64 Infinity 2.000 S65 Infinity 33.0001.60859 46.4 S66 Infinity 5.000 IMAGE Infinity Note: Maximum imagediameter = 11.0 mm *Surface profiles of aspheric surfaces S11, S14, S28,S42, S45 and S50 are governed by the following conventional equation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor The coefficients for the surface S11 are: the surface S42 are: K =−0.2197954 K = −0.0460624 A = 9.0593667e−009 A = −2.6257869e−007 B =1.7844857e−013 B = −2.5945471e−010 C = 1.5060271e−017 C = 2.4316558e−013D = −9.7397917e−023 D = −1.2995378e−016 The coefficients for Thecoefficients for the surface S14 are: the surface S45 are: K = 0.7048333K = 0.0 A = −3.0463508e−007 A = −1.1056187e−005 B = −1.1451797e−010 B =2.8606310e−008 C = 3.4844023e−014 C = −1.2655154e−010 D =−2.2107339e−017 D = 2.2826095e−013 The coefficients for The coefficientsfor the surface S28 are: the surface S50 are: K = −0.9252575 K = 0.0 A =−1.8743376e−007 A = −1.8976230e−006 B = −1.0562170e−009 B =1.2489903e−009 C = 2.8892387e−012 C = −2.3703340e−012 D =−3.6671423e−015 D = 3.0161146e−015 VARIABLE THICKNESS POSITIONS AND DATAP1 P2 P3 P4 P5 P6 P7 P8 EFL 7.257 9.008 16.013 36.022 82.023 174.970399.652 900.099 F/No. 1.450 1.450 1.450 1.450 1.450 2.000 4.000 5.000S12 1.000 23.202 72.004 118.539 150.121 162.578 162.380 162.474 S19243.711 218.457 160.764 96.265 43.111 0.500 57.093 0.500 S26 1.000 4.08012.979 30.924 52.631 82.760 26.357 82.523 S43 142.978 142.908 142.764142.760 142.409 140.110 89.130 81.860 S47 8.255 8.273 8.377 8.434 8.5404.765 3.198 5.165 S62 19.000 19.000 19.000 19.000 19.000 25.160 77.70383.508 Surface Groups Focal Lengths S1-S12 266.611 S13-S19 −46.300S20-S26 91.566 S27-S43 55.841 S44-S47 −32.720 S48-S62 42.594 SurfaceGroup Magnifications Surfaces P1 M′ P1 MP′ P2 M′ P2 MP′ P3 M′ P3 MP′ P4M′ P4 MP′ S1-S12 0.000 0.754 0.000 0.672 0.000 0.492 0.000 0.320 S13-S19−0.238 7.670 −0.268 7.215 −0.374 6.275 −0.599 5.828 S20-S26 −0.350 0.876−0.385 0.843 −0.495 0.746 −0.699 0.550 S27-S43 0.871 −1.159 0.870 −1.1590.854 −1.159 0.844 −1.159 S44-S47 0.321 −2.846 0.322 −2.829 0.325 −2.7940.327 −2.793 S48-S62 −1.170 −0.304 −1.170 −0.305 −1.170 −0.308 −1.170−0.308 Surfaces P1 M′ P5 MP′ P6 M′ P6 MP′ P7 M′ P7 MP′ P8 M′ P8 MP′S1-S12 0.000 0.195 0.000 0.123 0.000 0.163 0.000 0.124 S13-S19 −1.0127.410 −1.390 −119.200 −1.382 4.682 −1.386 −141.400 S20-S26 −0.945 −0.312−1.275 −0.017 −0.715 0.599 −1.279 −0.014 S27-S43 0.834 −1.159 0.833−1.159 0.774 −1.159 0.826 −1.159 S44-S47 0.330 −2.712 0.338 −2.278 0.769−0.501 0.856 −0.451 S48-S62 −1.170 −0.313 −1.315 −0.361 −2.549 −0.731−2.693 −0.727 Where, P1 M′ is lens group magnification of lens groupwhich equals (entrance marginal ray angle)/exit marginal ray angle) and,P1 MP′ is lens group magnification which equals entrance principal rayangle/exit principal ray angle and so on, up to P8 M′ and P8 MP′; thefirst two characters representing position number, for example P1 M′ andP1 MP′ are for position 1.

TABLES FOR FIGS. 7A & 7B LENS SYSTEM OPTICAL PRESCRIPTION Glass GlassSurface Radius Thickness Index Dispersion OBJECT Infinity Infinity S11273.174 10.255 1.80099 35.0 S2 475.265 1.538 S3 510.054 10.255 1.8009935.0 S4 279.310 14.066 S5 459.720 19.331 1.49699 81.6 S6 21434.630 0.308S7 800.941 10.451 1.49699 81.6 S8 27454.520 0.308 S9 309.779 13.3341.49699 81.6 S10 634.103 0.308 S11 361.606 17.818 1.49699 81.6 S122023.306 0.308 S13* 172.930 25.353 1.49699 81.6 S14 568.502 Variable S15330.425 2.070 1.77249 49.6 S16* 73.838 18.829 S17 726.741 2.051 1.7724949.6 S18 102.189 25.577 S19* −73.683 6.352 1.77249 49.6 S20* 359.7989.948 1.80809 22.8 S21 −116.821 Variable S22 −176.211 5.797 1.49699 81.6S23 −69.609 0.003 S24 144.415 20.317 1.49699 81.6 S25 −85.878 2.0511.80349 30.4 S26 −282.651 0.000 S27 85.718 6.142 1.49699 81.6 S28157.754 Variable STOP Infinity 22.498 S30* −34.201 2.051 1.60729 59.4S31 42.409 2.743 1.69894 30.1 S32 101.162 4.085 S33 −82.300 3.5891.60311 60.7 S34 −90.892 3.444 1.69894 30.1 S35 −39.457 6.472 S36 51.2007.178 1.49699 81.6 S37 55.671 15.382 S38 67.546 6.750 1.49699 81.6 S39−47.804 3.076 1.87399 35.3 S40 −74.620 0.018 S41 95.357 3.076 1.8739935.3 S42 35.060 30.000 1.43875 95.0 S43 −130.232 68.459 S44 Infinity2.051 S45 Infinity 2.051 1.77249 49.6 S46 −341.189 8.763 S47* −30.7654.102 1.78469 26.3 S48 −36.525 21.109 1.51680 64.2 S49 −30.389 0.308 S50−160.796 14.522 1.51680 64.2 S51 −66.413 0.308 S52 461.095 8.390 1.5168064.2 S53 −109.832 7.208 S54* 247.113 3.076 1.84666 23.8 S55 57.34810.868 1.49699 81.6 S56 −56.360 0.289 S57 −73.106 5.307 1.63853 55.4 S58−44.690 Variable S59 −28.736 3.076 1.83400 37.2 S60 115.838 2.771 S61−31.347 2.871 1.83480 42.7 S62 −73.220 2.468 S63 −57.858 7.254 1.8466523.9 S64 −24.994 0.005 S65 −29.067 2.871 1.80400 46.6 S66 −49.737Variable S67 507.291 2.051 1.74319 49.3 S68 104.703 7.178 1.49699 81.6S69 −76.662 Variable S70* 69.871 8.624 1.49699 81.6 S71 −663.734 8.908S72 −155.686 3.076 1.84665 23.9 S73 −1137.705 0.202 S74 54.109 8.0501.49699 81.6 S75 −73.493 0.393 S76 −66.184 2.871 1.74319 49.3 S77−99.535 19.484 S78 Infinity 13.537 1.51633 64.1 S79 Infinity 2.051 S80Infinity 33.841 1.60859 46.4 S81 Infinity 5.019 IMAGE Infinity Note:Maximum image diameter = 11.0 mm *Surface profiles of aspheric surfacesS13, S16, S19, S20, S30, S47, S54 and S70 are governed by the followingconventional equation: $\begin{matrix}{Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}} +}} \\{{(E)Y^{12}} + {(F)Y^{14}} + {(G)Y^{16}}}\end{matrix}\quad$ where: CURV = 1/(Radius of Surface) Y = Apertureheight, measured perpendicular to optical axis K, A, B, C, D, E, F, G =Coefficients Z = Position of surface profile for a given Y value, asmeasured along the optical axis from the pole (i.e. axial vertex) of thesurface. The coefficients for the The coefficients for the Thecoefficients for the surface S13 are: surface S20 are: surface S54 are:K = −0.1600976 K = 0.0 K = 0.0 A = 6.9210418e−009 A = 3.4619978e−008 A =−2.743254e−006 B = 2.2313210e−013 B = 4.2692157e−011 B = −2.133804e−009C = 1.1852054e−017 C = −7.0823340e−014 C = 1.668568e−011 D =−2.0918949e−021 D = −2.3957687e−017 D = −1.9544629e014 E =2.2579263e−025 E = 5.4513203e−020 E = 0.0 F = 8.1799420e−030 F =−1.4597367e−023 F = 0.0 G = −1.2582071e−033 G = −4.1263059e−027 G = 0.0The coefficients for the The coefficients for the The coefficients forthe surface S16 are: surface S30 are: surface S70 are: K = 0.9059289 K =−0.8025959 K = −2.3 A = −4.3564263e−007 A = −3.8556154e−007 A =3.877213e−007 B = −1.3760665e−010 B = −5.4410316e−010 B = 4.916800e−010C = 1.1349273e−014 C = 7.0427510e−012 C = −1.461192e−012 D =−3.8588303e−017 D = −8.5740313e−015 D = −3.258352e−017 E =1.5211558e−020 E = −5.2635786e−017 E = 4.664784e−018 F = −5.1726796e−025F = 1.0608042e−019 F = −4.216175e−021 G = −2.0900671e−027 G =7.5783088e−023 G = 0.0 The coefficients for the The coefficients for thesurface S19 are: surface S47 are: K = 0.0 K = 0.0 A = −6.5866466e−008 A= −1.2184510e−005 B = −3.2305127e−011 B = 1.2115245e−007 C =−3.5095033e−014 C = −3.0828524e−010 D = 4.0315700e−017 D =−5.7252449e−014 E = −6.1913043e−021 E = 0.0 F = −2.4403843e−023 F = 0.0G = 9.0865109e−027 G = 0.0 VARIABLE THICKNESS POSITIONS AND DATA P1 P2P3 P4 P5 P6 P7 EFL  7.257  12.152  35.981  82.040 145.068 736.9342088.142 F/No.  1.450  1.450  1.450  1.450  1.450  7.200  12.500 S14 1.026  51.867 122.026 160.824 167.824 157.900  167.823 S21 262.564202.199 103.948  49.493  0.000  34.351   0.000 S28  1.563  11.088 39.178  55.576  97.329  72.903  97.329 S58  8.616  8.616  8.616  8.616 8.616  99.467  105.316 S66 111.358 111.358 111.358 111.358 111.358 53.699   0.000 S69  38.387  38.387  38.387  38.387  38.387  5.195 53.100 Surface Groups Focal Lengths  S1-S14 283.564 S15-S21 −52.598S22-S28 102.619 S29-S58 51.668 S59-S66 −29.319 S67-S69 178.034 S70-S7770.650 Surface Group Magnifications Surfaces P1 M′ P1 MP′ P2 M′ P2 MP′P3 M′ P3 MP′ P4 M′ P4 MP′ S1-S14 0.000 0.740 0.000 0.564 0.000 0.3180.000 0.179 S15-S21 −0.260 7.365 −0.347 6.511 −0.644 6.193 −1.207 7.342S22-S28 −0.369 0.833 −0.462 0.740 −0.736 0.466 −0.896 0.306 S29-S58−2.392 −0.356 −2.392 −0.356 −2.392 −0.356 −2.392 −0.356 S59-S66 −0.28225.995 −0.282 25.995 −0.282 25.993 −0.282 25.994 S67-S69 14680.000 0.23114680.000 0.231 14680.000 0.231 14680.000 0.231 S70-S77 0.000 0.4470.000 0.447 0.000 0.447 0.000 0.447 Surfaces P5 M′ P5 MP′ P6 M′ P6 MP′P7 M′ P7 MP′ S1-S14   0.000  0.117  0.000  0.174  0.000  0.117 S15-S21  −1.468 −19.350  −1.150 14.886 −1.468 −19.350 S22-S28   −1.303  −0.101 −1.065  0.137 −1.303  −0.101 S29-S58   −2.392  −0.356  −2.392 −0.356−2.392  −0.356 S59-S66   −0.282  25.994  −2.227  0.319 −4.006  0.300S67-S69 14680.000  0.231 271.410  2.365 81.569  1.386 S70-S77   0.000 0.447  −0.001 −0.374 −0.005  −1.131 Where, P1 M′ is lens groupmagnification of lens group which equals (entrance marginal rayangle)/(exit marginal ray angle) and, P1 MP′ is lens group magnificationwhich equals entrance principal ray angle/exit principal ray angle andso on, up to P7 M′ and P7 MP′; the first two characters representingposition number, for example P1 M′ and P1 MP′ are for position 1.

TABLES FOR FIGS. 8A & 8B LENS SYSTEM OPTICAL PRESCRIPTION Glass GlassSurface Radius Thickness Index Dispersion OBJECT Infinity Infinity S1−763.589 10.000 1.80099 35.0 S2 408.783 15.991 S3 1218.452 22.5001.49699 81.6 S4 −948.218 0.100 S5 4440.119 19.600 1.49699 81.6 S6−478.965 0.100 S7 355.717 24.300 1.49699 81.6 S8 −1197.673 0.100 S9168.455 28.500 1.49699 81.6 S10 686.627 Variable S11 240.261 2.6501.77249 49.6 S12* 58.196 12.668 S13 307.706 2.900 1.77249 49.6 S14100.924 19.233 S15 −70.095 3.050 1.77249 49.6 S16 236.075 14.100 1.8466623.8 S17 −126.479 Variable S18 −420.335 9.200 1.49699 81.6 S19 −81.3550.126 S20 155.733 15.650 1.49699 81.6 S21 −98.523 2.750 1.80099 35.0 S22−285.204 10.687 S23 76.070 7.900 1.49699 81.6 S24 118.043 Variable STOPInfinity 6.800 S26* −35.243 6.500 1.60674 45.1 S27 55.360 0.106 S2855.900 4.050 1.75519 27.5 S29 155.439 4.934 S30 −63.039 5.050 1.8051825.4 S31 −39.609 2.240 S32 56.818 10.900 1.45599 90.3 S33 −43.388 2.1501.80099 35.0 S34 −61.503 2.158 S35 107.501 2.100 1.80099 35.0 S36 29.89611.600 1.49699 81.6 S37 166.103 78.890 S38 59.002 9.670 1.83741 25.4 S39−405.826 20.924 S40 −22.134 19.750 1.80099 35.0 S41 −33.299 5.803 S42−129.563 12.646 1.49699 81.6 S43 −52.914 0.152 S44 59.828 5.419 1.4969981.6 S45 −209.080 0.100 S46 37.693 6.143 1.74099 52.7 S47 177.702Variable S48 −106.846 1.600 1.83480 42.7 S49 21.576 6.448 S50 −27.6976.650 1.80099 35.0 S51 7367.260 0.829 S52 129.249 5.126 1.84583 24.0 S53−46.358 Variable S54 538.505 1.500 1.80099 35.0 S55 95.344 11.3951.60300 65.5 S56 −60.650 Variable S57 87.009 5.185 1.48749 70.2 S58−165.647 1.434 S59 −85.357 1.500 1.80518 25.4 S60 −1236.715 0.100 S6150.007 7.563 1.69472 54.5 S62 549.061 18.000 S63 Infinity 13.537 1.5163364.1 S64 Infinity 2.051 S65 Infinity 33.841 1.60859 46.4 S66 InfinityVariable IMAGE Infinity Note: Maximum image diameter = 11.0 mm *Surfaceprofiles of aspheric surfaces S12 and S26 are governed by the followingconventional equation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor the surface S12 are: K = 0.0 A = 1.3820532e−007 B = −2.7133115e−011C = −9.2535195e−015 D = 3.3313103e−018 The coefficients for the surfaceS26 are: K = −0.5520119 A = −1.0148386e−006 B = −5.9646048e−011 C =−1.3030573e−013 D = 3.2918363e−016 VARIABLE THICKNESS POSITIONS AND DATAP1 P2 P3 P4 P5 P6 P7 EFL 7.274 12.145 36.011 82.004 144.947 738.7762095.406 F/No. 1.450 1.450 1.450 1.450 1.450 9.400 14.100 S10 3.15450.878 126.861 163.460 167.963 167.403 168.654 S17 271.009 213.056113.646 61.255 10.607 68.828 3.277 S24 2.350 12.345 35.982 51.876 97.92240.276 104.616 S47 4.633 5.482 4.658 5.264 6.015 53.226 73.878 S53105.364 104.868 105.482 104.798 103.775 14.725 2.050 S56 1.550 1.5501.550 1.550 1.550 43.752 35.462 S66 4.969 4.799 4.853 4.815 5.202 4.8185.114 Surface Groups Focal Lengths S1-S10 262.599 S11-S17 −50.895S18-S24 98.756 S25-S47 37.686 S48-S53 −25.559 S54-S56 106.555 S57−S6281.336 Surface Group Magnifications Surfaces P1 M′ P1 MP′ P2 M′ P2 MP′P3 M′ P3 MP′ P4 M′ P4 MP′ S1-S10 0.000 0.805 0.000 0.626 0.000 0.3370.000 0.191 S11-S17 −0.248 7.962 −0.323 7.245 −0.625 7.155 −1.136 9.531S18-S24 −0.349 0.734 −0.431 0.633 −0.680 0.394 −0.831 0.233 S25-S47−1.752 −0.293 −1.612 −0.293 −1.683 −0.293 −1.613 −0.293 S48-S53 −0.5055.934 −0.574 4.957 −0.532 5.900 −0.571 5.176 S54-S56 −1.558 1.108 −1.5291.487 −1.539 1.120 −1.533 1.378 S57-S62 0.233 1.240 0.235 3.217 0.2341.263 0.234 2.205 Surfaces P5 M′ P5 MP′ P6 M′ P6 MP′ P7 M′ P7 MP′ S1-S100.000 0.130 0.000 0.184 0.000 0.120 S11-S17 −1.263 −8.111 −1.246 6.886−1.285 −6.384 S18-S24 −1.324 −0.233 −0.748 0.350 −1.444 −0.301 S25-S47−1.813 −0.293 −1.890 −0.293 −2.412 −0.293 S48-S53 −0.496 4.492 −3.5240.483 −4.060 0.347 S54-S56 −1.600 1.750 −1.939 2.244 −1.904 1.880S57-S62 0.230 −29.370 0.234 −0.833 0.231 −1.610 Where, P1 M′ is lensgroup magnification of lens group which equals (entrance marginal rayangle)/(exit marginal ray angle) and, P1 MP′ is lens group magnificationwhich equals entrance principal ray angle/exit principal ray angle andso on, upto P7 M′ and P7 MP′; the first two characters representingposition number, for example P1 M′ and P1 MP′ are for position 1.

TABLES FOR FIGS. 9A & 9B LENS SYSTEM OPTICAL PRESCRIPTION Glass GlassSurface Radius Thickness Index Dispersion OBJECT Infinity Variable S1Infinity 50.000 S2 −621.758 5.169 1.69350 53.2 S3 457.301 Variable S4−2452.883 4.799 1.80518 25.4 S5 599.599 Variable S6 911.220 25.0821.45599 90.3 S7 −497.020 0.100 S8 −2000.000 0.000 S9 1000.000 0.000 S102062.549 12.736 1.49699 81.6 S11 −1165.481 Variable S12 963.440 19.7401.49699 81.6 S13 −560.694 0.200 S14 382.994 19.312 1.49699 81.6 S15−17187.180 0.200 S16 191.959 26.185 1.43875 95.0 S17 702.850 0.000 S18324.818 Variable S19 130.133 3.120 1.77249 49.6 S20* 40.551 15.089 S2187.300 2.500 1.77249 49.6 S22 70.260 14.709 S23 −76.831 2.730 1.7724949.6 S24 108.868 11.313 1.84666 23.8 S25 −166.114 Variable S26 2466.51512.326 1.49699 81.6 S27 −72.273 0.200 S28 114.639 17.864 1.49699 81.6S29 −80.007 3.100 1.80099 35.0 S30 −402.245 0.200 S31 56.927 6.3641.48749 70.2 S32 83.100 Variable STOP Infinity 6.855 S34* −32.543 2.0001.60311 60.7 S35 −178.894 11.407 S36 −41.737 3.274 1.84666 23.8 S37−32.963 0.200 S38 49.510 12.747 1.49699 81.6 S39 −39.721 2.400 1.8009935.0 S40 −53.729 0.200 S41 −163.422 1.850 1.80439 39.6 S42 26.111 9.2211.49699 81.6 S43 −156.748 58.646 S44 44.245 2.533 1.80439 39.6 S451686.200 39.233 S46 −21.116 6.938 1.77249 49.6 S47 −21.969 14.095 S4892.954 2.220 1.60300 65.5 S49 −59.449 0.200 S50 20.331 2.228 1.6222953.2 S51 47.914 Variable S52 −116.378 0.950 1.83480 42.7 S53 34.3693.756 S54 −16.771 0.950 1.81600 46.6 S55 −36.990 1.142 S56 −21.55217.886 1.78469 26.3 S57 −26.412 Variable S58 −293.612 4.856 1.60311 60.7S59 −78.391 0.200 S60 272.204 5.642 1.49699 81.6 S61 −126.344 0.200 S62124.541 7.681 1.49699 81.6 S63 −102.092 2.500 1.80518 25.4 S64 −874.2680.200 S65 400.000 0.000 S66 38.596 8.430 1.45599 90.3 S67 211.910 6.207S68 Infinity 0.500 S69 123.725 2.000 1.81600 46.6 S70 39.478 7.176 S71−84.356 2.000 1.74099 52.7 S72 36.196 18.326 1.84666 23.8 S73 210.7240.984 S74 Infinity 7.645 S75 105.952 3.999 1.49699 81.6 S76 −91.2500.200 S77 46.317 5.948 1.60300 65.5 S78 −69.543 1.500 1.84666 23.8 S79166.511 22.000 S80 Infinity 13.200 1.51633 64.1 S81 Infinity 2.000 S82Infinity 33.000 1.60859 46.4 S83 Infinity 0.000 S84 Infinity 0.000 IMAGEInfinity Note: Maximum image diameter = 11.0 mm *Surface profiles ofaspheric surfaces S20 and S34 are governed by the following conventionalequation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor the surface S20 are: K = −0.3254663 A = −3.65160e−007 B =−1.14704e−010 C = −5.60564e−014 D = −5.86283e−018 The coefficients forthe surface S34 are: K = 0.348034 A = 1.350560e−006 B = 2.453070e−009 C= −2.820340e−012 D = 4.745430e−015 VARIABLE THICKNESS POSITIONS AND DATAP1 P2 P3 P4 P5 P6 EFL 7.278 7.278 7.278 8.817 12.199 18.641 F/No. 1.7491.749 1.749 1.749 1.749 1.749 SO Infinity 5322.600 2499.900 InfinityInfinity Infinity S3 17.233 50.424 82.285 17.233 17.233 17.233 S5 3.8568.913 13.211 3.856 3.856 3.856 S11 74.605 36.357 0.200 74.605 74.60574.605 S18 0.200 0.200 0.200 26.070 64.733 106.272 S25 300.191 300.191300.191 272.377 230.274 183.410 S32 1.334 1.334 1.334 3.266 6.708 12.035S51 1.647 1.647 1.647 1.647 1.647 1.647 S57 80.778 80.778 80.778 80.77880.778 80.778 VARIABLE THICKNESS POSITIONS AND DATA P7 P8 P9 P10 P11 P12EFL 32.734 60.449 94.190 123.985 206.250 284.791 F/No. 1.749 1.749 1.8902.020 2.160 2.700 SO Infinity Infinity Infinity Infinity InfinityInfinity S3 17.233 17.233 17.233 17.233 17.233 17.233 S5 3.856 3.8563.856 3.856 3.856 3.856 S11 74.605 74.605 74.605 74.605 74.605 74.605S18 148.849 183.007 201.036 209.783 216.511 215.851 S25 132.062 85.94857.616 42.322 21.856 15.570 S32 20.806 32.763 43.065 49.609 63.17070.310 S51 1.647 1.647 2.130 3.050 8.806 15.438 S57 80.778 80.778 80.29479.375 73.618 66.987 VARIABLE THICKNESS POSITIONS AND DATA P13 P14 P15P16 P17 EFL 717.193 2092.160 2092.160 2092.160 2092.160 F/No. 5.20013.750 13.750 13.750 17.490 SO Infinity Infinity 8708.000 4050.0002499.900 S3 17.233 17.233 37.759 59.403 82.285 S5 3.856 3.856 7.17810.305 13.211 S11 74.605 74.605 50.757 25.988 0.200 S18 211.275 208.261208.261 208.261 208.261 S25 5.736 0.200 0.200 0.200 0.200 S32 84.68093.262 93.262 93.262 93.262 S51 39.946 82.225 82.225 82.225 82.225 S5742.480 0.200 0.200 0.200 0.200 Surface Groups Focal Lengths S2-S3−379.209 S4-S5 −597.975 S6-S11 484.131 S12-S18 229.394 S2-S18 262.190S19-S25 −49.050 S26-S32 79.931 S33-S51 41.254 S52-S57 −26.810 S58-S7970.920 Surface Group Magnifications Surfaces P1 M′ P1 MP′ P2 M′ P2 MP′P3 M′ P3 MP′ P4 M′ P4 MP′ S2-S3 0.000 1.732 0.066 1.710 0.129 1.6960.000 1.971 S4-S5 0.599 1.754 0.594 1.563 0.59 1.425 0.599 2.388 S6-S112.150 0.529 2.229 0.608 2.304 0.682 2.150 0.374 S12-S18 −0.537 0.642−0.537 0.642 −0.537 0.642 −0.537 0.53 S2-S18 0.000 1.030 −0.047 1.043−0.094 1.058 0.000 0.934 S19-S25 −0.185 8.447 −0.185 8.447 −0.185 8.447−0.206 7.952 S26-S32 −0.252 0.756 −0.252 0.756 −0.252 0.756 −0.252 0.731S33-S51 −1.446 −0.378 −1.446 −0.378 −1.446 −0.378 −1.442 −0.378 S52-S57−0.673 6.392 −0.673 6.392 −0.673 6.392 −0.676 6.392 S58-S79 −0.611 0.966−0.611 0.966 −0.611 0.966 −0.611 0.966 Surfaces P5 M′ P5 MP′ P6 M′ P6MP′ P37 M′ P7 MP′ P8 M′ P8 MP′ S2-S3 0.000 2.695 0.000 6.440 0.000−4.655 0.000 −1.279 S4-S5 0.599 −24.64 0.599 −0.414 0.599 0.216 0.5990.403 S6-S11 2.150 −0.033 2.150 −1.271 2.150 −127.8 2.150 4.484 S12-S18−0.537 0.365 −0.537 0.187 −0.537 0.004 −0.537 −0.147 S2-S18 0.000 0.7880.000 0.633 0.000 0.473 0.000 0.341 S19-S25 −0.245 7.233 −0.31 6.531−0.424 6.046 −0.601 6.421 S26-S32 −0.319 0.688 −0.386 0.622 −0.496 0.512−0.646 0.362 S33-S51 −1.445 −0.378 −1.448 −0.378 −1.448 −0.378 −1.449−0.378 S52-S57 −0.673 6.392 −0.671 6.392 −0.671 6.392 −0.67 6.392S58-S79 −0.611 0.966 −0.612 0.966 −0.612 0.966 −0.612 0.966 Surfaces P9M′ P9 MP′ P10 M′ P10 MP′ P11 M′ P11MP′ P12 M′ P12MP′ S2-S3 0.000 −0.7360.000 −0.549 0.000 −0.387 0.000 −0.365 S4-S5 0.599 0.468 0.599 0.4960.599 0.522 0.599 0.526 S6-S11 2.150 3.296 2.150 2.964 2.150 2.701 2.1502.668 S12-S18 −0.537 −0.234 −0.537 −0.279 −0.537 −0.330 −0.537 −0.338S2-S18 0.000 0.265 0.000 0.225 0.000 0.180 0.000 0.173 S19-S25 −0.7718.327 −0.894 11.79 −0.983 −18.95 −1.004 −14.68 S26-S32 −0.770 0.233−0.846 0.152 −1.064 −0.084 −1.092 −0.107 S33-S51 −1.431 −0.378 −1.406−0.378 −1.344 −0.378 −1.359 −0.378 S52-S57 −0.692 5.731 −0.728 4.790−0.916 2.531 −1.194 1.491 S58-S79 −0.611 1.263 −0.611 2.227 −0.611−2.992 −0.610 −1.604 Surfaces P13M′ P13MP′ P14M′ P14MP′ P15M′ P15MP′P16M′ P16MP′ S2-S3 0.000 −0.351 0.000 −0.348 0.041 −0.294 0.085 −0.24S4-S5 0.599 0.529 0.599 0.529 0.596 0.529 0.593 0.529 S6-S11 2.150 2.6462.150 2.642 2.199 2.691 2.250 2.742 S12-S18 −0.537 −0.344 −0.537 −0.345−0.537 −0.345 −0.537 −0.345 S2-S18 0.000 0.169 0.000 0.168 −0.029 0.145−0.061 0.12 S19-S25 −0.919 −5.386 −0.870 −3.955 −0.869 −3.955 −0.869−3.955 S26-S32 −1.351 −0.287 −1.561 −0.395 −1.561 −0.395 −1.561 −0.395S33-S51 −1.719 −0.378 −2.606 −0.378 −2.61 −0.378 −2.612 −0.378 S52-S57−2.093 0.631 −3.758 0.316 −3.685 0.316 −3.626 0.316 S58–S79 −0.613−1.659 −0.600 −7.955 −0.610 −7.955 −0.619 −7.955 Surfaces P17M′ P17MP′S2-S3 0.129 −0.183 S4-S5 0.590 0.528 S6-S11 2.304 2.795 S12-S18 −0.537−0.345 S2-S18 −0.094 0.093 S19-S25 −0.869 −3.955 S26-S32 −1.561 −0.395S33-S51 −2.612 −0.378 S52-S57 −3.629 0.316 S58-S79 −0.618 −7.955 Where,P1 M′ is lens group magnification of lens group which equals (entrancemarginal ray angle)/(exit marginal ray angle) and, P1 MP′ is lens groupmagnification which equals entrance principal ray angle/exit principalray angle and so on, upto P17 M′ and P17 MP′; the first two charactersrepresenting position number, for example P1 M′ and P1 MP′ are forposition 1. The group of elements defined by surfaces 69 through 73 istranslated in a direction perpendicular to the optical axis tocompensate for image vibration

In the lens system optical prescriptions provided above for each of thefour embodiments, each surface of a lens element identified in the lefthand column (“Surface”), the radius of that surface in the second column(“Radius”), the thickness on the optical axis between that surface andthe next surface, whether glass or air, in the third column(“Thickness”), the refractive indices of the glass lens elements setforth in the fourth column (“Glass Index”), and the dispersion valuesfor the lens elements (“Glass Dispersion”) set forth in the fifthcolumn. The surface numbers in the first column “Surface” represent thesurfaces numbered from left-to-right in the Figures in the conventionalmanner, namely from object space to image space.

In the left hand or “Surface” column of each lens system opticalprescription provided above, the object to be imaged (e.g.,photographed) is identified as “OBJECT”, the adjustable iris or stop isidentified as “STOP”, and the final image is identified as “IMAGE”. Theadjustable spaces between lens elements, such as on either side ofmovable zoom groups, are identified as “Variable” in the third orThickness column of the lens system optical prescription. The EFL,Radius and Thickness dimensions are given in millimeters with theThickness being the distance after that surface on the optical axis.When two surfaces of adjacent elements have the same radius and arecoincident, as in a doublet or triplet, only one surface is identifiedin the first or “Surf” column.

For each of the four embodiments, Aspheric Coefficients for each of theaspheric surfaces are provided following the table of opticalprescriptions.

In addition, for each of the four embodiments, tables of the variablethickness positions for various surfaces in each lens system opticalprescription are provided which identify positions in the format “Px”for various surfaces (corresponding to entries in the Surface column ofthe optical prescription tables). The effective focal length (EFL) andthe “f” number (F/No.) are also provided for each position.

Now each of the four embodiments of FIGS. 6A-9B will be describedbriefly to identify some of their differences. The embodiment of FIGS.6A and 6B has an effective focal length range of about 7.25 mm to 900mm, which provides a zoom ratio of about 125:1, while using threemovable zoom lens groups, namely, Zoom 1, Zoom 2, and Zoom 3, with afocus lens group Focus at the object space end of the lens. The Zoom 3group actually is comprised of two groups of elements that have a smallamount of movement between surfaces S47 and S48 (compare FIGS. 6A and6B). The embodiment of FIGS. 7A and 7B has an effective focal lengthrange of about 7.27 mm to 2088 mm, which provides a zoom ratio of about287:1, with four movable zoom lens groups (Zoom 1, 2, 3 and 4) and afocus lens group. The embodiment of FIGS. 8A and 8B has an effectivefocal length range of about 7.27 mm to 2095 mm, which also provides azoom range of about 287:1, with four moving zoom lens groups and a focuslens group, which is very similar to the performance of the lensembodiment of FIGS. 7A and 7B. Similarly, the embodiment of FIGS. 9A and9B has an effective focal length range of about 7.27 mm to 2092 mm,which also provides a zoom ratio of about 287:1, but uses only threemoving zoom lens groups. Each of these four embodiments includes pluralaspheric surfaces with the embodiments of the FIGS. 8A-8B and 9A-9Bhaving only two such surfaces while the embodiment of FIGS. 7A-7Bincludes eight such surfaces, as indicated in the lens system opticalprescriptions. The embodiment of FIGS. 9A and 9B also includes opticalimage stabilization lens elements near the camera end of the lens systemsimilar to those included in the embodiment of FIGS. 10-62, which willbe described below.

Detailed Description of the Embodiment of FIGS. 10-62. As noted above inthe section entitled “Brief Description of the Drawings,” FIGS. 10-62all relate to a single embodiment of the present invention that isdirectly and immediately applicable to the broadcast television market,although other markets are also available and various other embodimentsand modifications of the invention may be more applicable to othermarkets. This embodiment of the compound zoom lens system of thisinvention has a zoom range of approximately 7 mm to 2100 mm in focallength, thereby providing a zoom ratio of about 300:1, which is morethan three times the zoom ratio presently available in broadcasttelevision zoom lens systems. Referring more particularly to the opticaldiagram of FIG. 10, the zoom lens system ZL is comprised of a focus lensgroup FG, a front zoom group FZG and a rear zoom group RZG. For thedescription of this embodiment, the lens system's stop is used as adivider between the “front” and “rear” of the lens. In terms of theterminology used in the “Description of Various Features of theInvention and the Disclosed Embodiments” set forth above, the focus lensgroup FG is the focus unit, the front zoom group FZG is the firstoptical unit, and the rear zoom group RZG includes a pupil imaging unitand an image stabilization unit, as well as the second optical unit.

The focus group FG is comprised of seven lens elements 1-7 with thefront lens element 1 being stationary whereby the lens may be sealed atthe front by fixing and sealing element 1 to the lens barrel (notshown). Lens element 2 comprises a first focus group FG1 and lenselements 3 and 4 comprise a second focus group FG2, both of which groupsare independently movable for achieving the desired focus at each focallength. Elements 5-7 of the focus group FG are stationary.

The front zoom group FZG has a first zoom group ZG1 comprised of lenselements 8-11 and a second zoom group ZG2 comprised of lens elements12-15, both of which zoom groups are independently movable. An iris oraperture stop STOP is positioned between the second zoom group ZG2 and afirst group RG1 that forms the front portion of the rear zoom group RZG.

First group RG1 is comprised of lens elements 16-25, which remainstationary. The intermediate image is formed between lens elements 22and 23 in the first group RG1. Although all of the lens elements 16-25of this first group RG1 remain stationary at all times, the intermediateimage moves along the optical axis between lens elements 22 and 23 atthe longer focal lengths without touching either of those elementsduring the zooming of the lens system between the maximum and minimumfocal lengths. The next lens group of the rear zoom group RZG is a thirdzoom group ZG3 comprised of lens elements 26-28 that are movableaxially. Next within the rear zoom group RZG is a second group RG2comprised of lens elements 29-33, which are stationary. The nextelements in the rear zoom group RZG comprise a stabilization group SGhaving a radial decentralization group SG1 with lens elements 34-36 andan axially adjustable group SG2 with lens elements 37-39. The three zoomgroups ZG1, ZG2 and ZG3 are independently movable along the optical axisfor developing the full range of the focal lengths of about 7 mm to 2100mm. Finally, although they are not part of the zoom lens system per se,FIG. 10 also illustrates two prism blocks 40 and 41 that emulate theconventional three CCD ⅔″ detectors of a video camera for completing theoptical diagram from object space to the final image.

The first or decentralization stabilization group SG1 is movableradially from the system's optical axis in any direction by about 0.5 mmor more in response to sensed vibrations of the lens to maintain thefinal image at the image plane in a stabilized location. The sensing ofvibrations and the movement of group SG1 may be accomplished by anyconventional means such as an accelerometer, a processor and a motorcontrolled by the processor in a closed loop system on a continuousbasis. The second or axial stabilization group SG2 is axially movablefor axial adjustment of about 1.25 mm or more in either direction forback focus adjustment. The second stabilization group SG2 may also bemoved axially forward a greater amount for extended close focus at shortfocal lengths of the lens. The light rays between the firststabilization group SG1 and the second stabilization group SG2, i.e.between lens elements 36 and 37, are substantially collimated wherebythe movements of those two groups for accomplishing stabilization,extending the close focus and adjusting the back focus do not cause anysignificant deterioration of the final image.

The decentralization stabilization group SG1 may also be used forcreating special effects by causing the lens group SG1 to move radiallyin a shaking pattern to thereby simulate the shaking caused, forexample, by an earthquake, a moving vehicle or explosions in a warmovie. Such special effects can also be produced by moving the lensgroup SG2 axially in an oscillatory fashion, which slightly defocusesthe picture. Radial movement of SG1 can also be combined with axialmovement of SG2 to create a different special effect.

The complete lens design of the zoom lens system ZL for the embodimentof FIGS. 10-62 is set forth below in the tables generally entitled“Tables for FIGS. 10 thru 62.” The Lens System Optical Prescriptiontable is similar to the foregoing lens prescriptions for the zoom lensesof FIGS. 6A-9B. A more detailed explanation of the tables is providedfollowing the tables.

TABLES FOR FIGS. 10 thru 62 LENS SYSTEM OPTICAL PRESCRIPTION SemiSurface Radius Thickness Glass Name Manufacturer Aperture OBJECTInfinity Variable S1 Infinity 50.000 142.85 S2 −553.385 5.200 SLAL13OHARA 111.77 S3 436.730 Variable 103.81 S4 −1545.910 4.900 STIH6 OHARA102.97 S5 682.341 Variable 101.63 S6 1644.762 19.482 SFPL52 OHARA 101.59S7 −467.261 0.730 101.38 S8 −2000.000 0.000 99.83 S9 4000.000 0.00099.22 S10 1463.863 12.601 SFPL51 OHARA 98.87 S11 −1094.948 Variable98.22 S12 1092.461 20.386 SFPL51 OHARA 100.60 S13 −480.155 0.730 101.05S14 362.425 21.232 SFPL51 OHARA 101.85 S15 −14624.000 0.730 101.37 S16181.063 24.150 SFPL53 OHARA 97.84 S17 477.885 0.000 96.42 S18 324.818Variable 95.12 S19 208.678 3.120 SLAH66 OHARA 38.27 S20* 40.147 6.11132.19 S21 67.136 3.150 SLAH59 OHARA 32.03 S22 56.870 14.527 30.64 S23−98.690 2.730 SLAH66 OHARA 30.54 S24 90.992 12.5065 STIH53 OHARA 33.74S25 −174.619 Variable 34.43 S26 764.771 14.926 SFPL52 OHARA 36.34 S27−66.842 0.400 36.91 S28 133.738 17.704 SFPL51 OHARA 36.84 S29 −69.9883.100 SLAM66 OHARA 36.62 S30 −1580.221 0.400 36.97 S31 65.214 9.613SNSL36 OHARA 37.33 S32 129.561 Variable 36.67 STOP Infinity 8.811 20.27S34* −36.392 2.044 SBSM14 OHARA 20.44 S35 −425.016 6.131 21.70 S36−43.308 5.233 STIH53 OHARA 21.88 S37 −33.861 0.200 22.78 S38 47.20313.980 SFPL51 OHARA 22.84 S39 −41.565 2.400 SLAM66 OHARA 22.59 S40−56.845 0.200 22.47 S41 −109.533 1.950 SLAH63 OHARA 21.13 S42 31.53210.159 SFPL51 OHARA 19.56 S43 −173.403 45.721 19.51 S44 47.891 4.513SLAH53 OHARA 15.23 S45 −2514.287 41.843 14.84 S46 −23.807 9.483 SLAH59OHARA 8.45 S47 −24.610 12.719 9.87 S48 61.223 3.114 SFPL51 OHARA 8.86S49 −45.071 0.150 8.71 S50 24.918 3.242 SBSM9 OHARA 8.83 S51 −516.606Variable 8.67 S52 −72.073 1.059 SLAL54 OHARA 7.15 S53 23.513 2.783 6.65S54 −18.951 0.900 SLAH59 OHARA 6.54 S55 −57.174 1.347 6.84 S56 −21.15021.292 SLAH60 OHARA 6.98 S57 −31.181 Variable 12.67 S58 −138.459 4.401SBAL22 OHARA 23.12 S59 −75.648 0.300 23.54 S60 606.713 5.842 SFPL51OHARA 23.89 S61 −96.488 0.300 23.97 S62 113.288 7.382 SFPL51 OHARA 23.55S63 −97.742 2.500 STIH6 OHARA 23.30 S64 −366.723 0.300 23.05 S65 400.0000.000 22.80 S66 38.760 8.585 SFPL52 OHARA 21.88 S67 269.438 5.901 21.07S68 115.000 0.450 18.30 S69 94.072 1.770 SLAL54 OHARA 18.00 S70 35.9827.000 16.65 S71 −90.502 2.010 SLAL8 OHARA 16.35 S72 29.972 6.150 STIH53OHARA 16.01 S73 82.308 2.725 15.75 S74 79.000 9.670 15.78 S75 76.2326.100 SPHM52 OHARA 15.87 S76 −75.003 0.761 15.66 S77 45.420 7.170 SFSL5OHARA 14.38 S78 −45.317 1.500 STIH53 OHARA 13.58 S79 348.342 18.54412.98 S80 Infinity 13.200 SBSL7 OHARA 10.30 S81 Infinity 2.000 9.00 S82Infinity 33.000 BAF52 SCHOTT 8.70 S83 Infinity 0.000 5.69 S84 Infinity0.000 IMAGE Infinity 0.000 Note: Maximum image diameter = 11.0 mm*Surface profiles of aspheric surfaces S20 and S34 are governed by thefollowing conventional equation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor The coefficients for the surface S20 are: the surface S34 are: K =−0.3564030 K = 0.4304790 A = −8.06827e−07 A = 9.57697e−07 B =−2.15109e−10 B = 1.31318e−09 C = −6.36649e−14 C = −1.45592e−12 D =−3.89379e−18 D = 3.19536e−15 VARIABLE THICKNESS POSITIONS AND DATA P1 P2P3 P4 P5 P6 P7 EFL 7.391 8.820 12.231 19.219 32.730 64.634 −93.220 F/No.1.949 1.949 1.949 1.949 1.949 1.949 2.010 S0 Infinity Infinity 5322.6302499.896 Infinity 5322.630 Infinity S3 19.882 19.882 49.699 78.33319.882 49.699 19.882 S5 5.690 5.690 10.880 15.384 5.690 10.879 5.690 S1171.522 71.522 36.516 3.376 71.522 36.516 71.522 S18 1.350 26.428 67.051110.745 155.094 189.151 203.856 S25 319.660 292.522 247.857 197.854142.790 92.653 65.474 S32 9.625 11.684 15.727 22.036 32.751 48.83061.304 S51 1.498 1.498 1.498 1.498 1.498 1.498 2.823 S57 63.257 63.25763.257 63.257 63.257 63.257 61.933 VARIABLE THICKNESS POSITIONS AND DATAP8 P9 P10 P11 P12 P13 P14 EFL 145.184 206.228 490.401 717.511 2065.045−3694.934 −920.968 F/No. 2.090 2.360 2.840 5.600 13.064 13.064 13.064 S05322.630 Infinity 5322.630 Infinity Infinity 8708.002 4050.000 S3 49.69919.882 49.699 19.882 19.882 38.428 57.882 S5 10.879 5.690 10.879 5.6905.690 9.057 12.294 S11 36.516 71.522 36.516 71.522 71.522 49.608 26.917S18 210.392 215.814 218.877 223.339 224.980 224.980 224.980 S25 50.04633.074 24.338 10.235 1.719 1.719 1.719 S32 70.197 81.746 87.419 97.063103.934 103.934 103.934 S51 4.711 9.572 14.559 31.080 63.536 63.53663.536 S57 60.044 55.183 50.196 33.675 1.220 1.220 1.220 VARIABLETHICKNESS POSITIONS AND DATA P15 P16 P17 P18 P19 P20 EFL −509.031−1739.084 −387.928 7.227 114.357 377.554 F/No. 16.750 5.600 5.600 1.9492.010 2.360 S0 2499.896 5322.630 2499.896 2499.896 2499.896 2499.896 S378.333 49.699 78.333 78.333 78.333 78.333 S5 15.384 10.879 15.384 15.38415.384 15.384 S11 3.376 36.516 3.376 3.376 3.376 3.376 S18 224.980223.339 223.339 1.350 203.856 215.814 S25 1.719 10.235 10.235 319.66065.474 33.074 S32 103.934 97.063 97.063 9.625 61.304 81.746 S51 63.53631.080 31.080 1.498 2.823 9.572 S57 1.220 33.675 33.675 63.257 61.93355.183 Surface Groups Focal Lengths S2-S3 −349.648 S4-S5 −581.962 S6-S7798.201 S10-S11 1258.758 S12-S13 672.072 S14-S15 709.848 S16-S17 646.676S19-S20 −64.565 S21-S22 −526.211 S23-S25 −554.999 S26-S27 135.208S28-S30 113230.702 S31-S32 240.348 S34-S35 −65.863 S36-S37 144.623S38-S40 60.255 S41-S43 −70.987 S44-S45 58.010 S46-S47 205.873 S48-S4952.593 S50-S51 38.634 S52-S53 −27.000 S54-S55 −34.933 S56-S57 −2495.053S58-S59 284.851 S60-S61 167.476 S62-S64 292.466 S66-S67 97.878 S69-S70−90.217 S71-S73 −72.295 S75-S76 61.902 S77-S79 1261.227 S80-S81 InfinityS82-S83 Infinity

The Lens System Optical Prescription table comprises the “Listing” forthe lens specification and numerically lists each lens “SURFACE” in theleft-hand column, but also includes dummy surfaces used in the designsuch as dummy surfaces S1, S8, S9, S18, S65, S74 and S84. The secondcolumn “Radius” lists the radius of the respective surfaces with anegative radius indicating that the center of curvature is to the left.The third column “Thickness” lists the thickness of the lens element orspace from that surface to the next surface on the optical axis. Thefourth column “Glass Name” lists the type of glass and the fifth column“Manufacturer” lists the manufacturer of each glass material. The fifthcolumn “Semi Aperture” provides a measurement of half the aperturediameter for each lens element.

In the left-hand column the legend “OBJECT” means the object to beimaged (e.g., photographed), the legend “STOP” means the iris or stop,and the legend “IMAGE” means the final image. Each of the surfaces isidentified by a numeral preceded by “S” to distinguish the surfaces fromthe numerals that identify the lens elements set forth on the subsequentpages comprising the 39 glass lens elements described above with respectto FIG. 10 and prisms 40 and 41 of the detector.

It should be noted that each of the thickness dimensions set forth inthe third column of the table listing the surfaces is the elementthickness or air space along the optical axis for the zoom lens systemZL set to the shortest focal lens (7.39 mm EFL) and focused at infinity.The air spaces adjacent the moving lens groups obviously will change in“thickness” for other focal lengths and focus distances.

For each aspheric surface, Aspheric Coefficients are provided followingthe table of optical prescriptions.

FIGS. 11-30 illustrate 20 representative positions for the zoom lenssystem of FIG. 10. These 20 positions are listed in the following Tableof Lens Positions:

TABLE OF LENS POSITIONS Paraxial EFL (mm) Focus Distance (mm) To Object*@ Infinity Focus “F” No. INF. 8758 5372 4100 2550 7.3909 1.95 1 188.8200 1.95 2 12.1938 1.95 3 18.6371 1.95 4 32.7300 1.95 5 60.2959 1.956 93.2199 2.01 7 19 127.2902 2.09 8 206.2278 2.36 9 20 297.4279 2.84 10717.5114 5.60 11 16 17 2065.0447 13.06 12 13 14  15# *The Focus Distanceis measured to the Object from the first refractive surface of the zoomlens system. #The “F” No. equals 16.75 at this position.

The twenty (20) positions were selected as representative of extremepositions of focal length and focus distance, as well as intermediatepositions, for establishing the representative performances of the zoomlens system ZL of FIG. 10. In other words, position 1 is at the minimumparaxial focal length (wide angle) of about 7.4 mm and focused atinfinity whereas position 18 is focused at 2550 mm (about eight feet)for the same focal length. Similarly, position 12 represents the longestparaxial focal length of about 2065 mm at infinity focus whereasposition 15 represents the focus at 2550 mm at the same paraxial focallength. The paraxial EFL in the first column is at infinity focus. The“f” numbers are at any given focus and at full aperture. The 12different focal lengths provide representative focal lengths over thefull range of the zoom lens system ZL. Also, it should be noted that theactual field of view as a result of distortion and the availablephysical overtravel of the zoom groups beyond data in the lens systemoptical prescription set forth below produces an apparent focal lengthrange of substantially 7.0 mm to 2100 mm, i.e. a zoom ratio of about300:1, with the distortion primarily influencing the reduction in theminimum paraxial EFL and the overtravel primarily influencing theincrease in the maximum paraxial EFL. At 2100 mm EFL with focus set ateight feet, the magnification is about 1.33:1.00 (object to image size).The nominal lens design for the embodiment of FIGS. 10-62 as reflectedin the lens optical prescription tables for FIGS. 10-62 is given at 77°F. (25° C., 298 K) and standard atmospheric pressure (760 mm Hg).

Referring now to FIGS. 11-30, the twenty positions 1-20 set forth in theforegoing lens system optical prescription and the preceding TABLE OFLENS POSITIONS are shown in that order. For example, FIG. 11 is anoptical diagram of the lens elements in Position 1, namely, a paraxialeffective focal length (EFL) of 7.391 mm and focused at infinity,wherein the first and second focus groups FG1 and FG2 are closelyseparated, the first and second zoom groups ZG1 and ZG2 are widelyseparated, and the third zoom group ZG3 is in its most forward position.On the other hand, FIG. 25 is the optical diagram representing Position15 with the largest focal length and shortest focus distance, whereinthe first and second focus groups FG1 and FG2 are both in their rearmostposition, the first and second zoom groups ZG1 and ZG2 are in a closelyspaced position but intermediately spaced between adjacent lens groups,and the third zoom group ZG3 is in the rearmost position.

FIGS. 31-34 are enlarged optical diagrams of only the seven focus groupFG elements 1-7 and illustrate representative Positions 1, 18, 12 and15, respectively. It should be noted that while the lens elementpositions in FIGS. 32 and 34 are the same, representing the focusdistance of 2550 mm, the ray tracings are different because of thedifference in the paraxial focal lengths from the minimum of about 7.4mm in FIG. 32 to the maximum of about 2065 mm in FIG. 34.

FIGS. 35 and 36 are enlarged optical diagrams illustrating the last lenselement 7 of the focus group FG and the first and second zoom groups ZG1and ZG2 in Positions 1 and 12, respectively, for the minimum and maximumparaxial focal lengths, respectively. Similarly, FIGS. 37 and 38represent the rear zoom group RZG with the third zoom group ZG3 in theforwardmost and rearmost Positions 1 and 12 representing the minimum andmaximum paraxial focal length positions, all respectively.

Referring now to FIGS. 39-58, the ray aberration graphs for Positions1-20, respectively, are shown in a conventional manner by five separategraphs with the maximum field height at the top and zero field height atthe bottom and for five wavelengths, as listed thereon. As will readilyappear to those skilled in the art, these performance curves establishthat in all 20 positions the zoom lens system performs exceptionallywell for current broadcast television NTSC quality and exceptionallywell for HDTV broadcast television quality. While FIG. 50 representingPosition 12, illustrates wide variations in the ray aberrations at thisfocal length and focused at infinity, the performance is satisfactorybecause the modulation transfer function is close to the diffractionlimit. Similarly, FIGS. 52 and 53, representing Positions 14 and 15,respectively, illustrate widely varying ray aberrations but are stillacceptable relative to diffraction limits for these close focus and longfocal length positions.

Referring now to FIG. 59, the cam graph for the first and second focusgroups FG1 and FG2 are shown (left and right, respectively) for the fullrange of focus travel thereof from infinity to close focus, with objectspace being to the left. The first and second focus groups FG1 and FG2move separately and not at precisely the same rate, even though thesolid cam lines in FIG. 59 look nearly parallel. The crosshatchedportions at the top and bottom of FIG. 59 allow for temperature changes,manufacturing tolerances and fabrication adjustments. Similarly, FIG. 60illustrates the cam graphs for the three zoom groups ZG1, ZG2 and ZG3from left to right, respectively, and it is readily apparent that allthree zoom groups move independently, although coordinated to achievethe desired focal lengths continuously over the entire range. FIG. 61 isa graph of the “f” number of the open stop relative to the paraxialeffective focal length. Similarly, FIG. 62 is a graph of the fullaperture full stop diameter relative to the paraxial effective focallength throughout the full range thereof.

DETAILED DESCRIPTION OF OTHER EMBODIMENTS

FIGS. 63 and 64 illustrate an example of another embodiment of thepresent invention. This embodiment of the zoom lens system is verysimilar to the embodiment of FIGS. 8A and 8B, except that a binary(diffractive) surface is provided. Specifically, a binary surface isprovided on the front surface (surface No. 3 in the prescription) of thesecond lens element. The lens system optical prescription is set forthbelow in the tables generally entitled “Tables for FIGS. 63 and 64.” Amore detailed explanation of the tables is provided following thetables.

TABLES FOR FIGS. 63 and 64 LENS SYSTEM OPTICAL PRESCRIPTION GlassSurface Radius Thickness Name OBJECT Infinity Infinity S1 −731.22210.000 LASF32 S2 390.798 15.991 S3# 827.075 22.500 BK7 S4 −1021.4180.100 S5 −1257.463 −19.600 BK7 S6 −780.160 0.100 S7 436.979 24.300 BK7S8 −835.454 0.100 S9 −170.301 28.500 BK7 S10 655.827 Variable S11278.083 2.650 S-LAH66 S12* 60.022 −12.668 S13 277.706 2.900 S-LAH66 S1498.325 −19.233 S15 −70.105 3.050 S-LAH66 S16 234.965 −14.100 S-TIH53 S17−127.001 Variable S18 −404.763 9.200 S-FPL51 S19 −80.933 0.126 S20−157.360 −15.650 S-FPL51 S21 −99.532 2.750 S-LAM66 S22 −284.625 −10.687S23 76.300 7.900 S-FPL51 S24 −118.669 Variable STOP Infinity 6.800 S26*−34.999 6.500 BAF4 S27 54.435 0.106 S28 55.347 4.050 S-TIH4 S29 −158.5044.934 S30 −64.093 5.050 S-TIH6 S31 −39.812 2.240 S32 56.945 −10.900S-FPL52 S33 −43.914 2.150 S-LAM66 S34 −61.923 2.158 S35 −106.356 2.100S-LAM66 S36 30.350 −11.600 S-FPL51 S37 −151.277 78.890 S38 57.056 9.670SF6 S39 −603.641 20.924 S40 −22.693 −19.750 S-LAM66 S41 −34.224 5.803S42 −129.563 −12.646 S-FPL51 S43 −52.914 0.152 S44 59.828 5.419 S-FPL51S45 −209.080 0.100 S46 37.693 6.143 S-LAL61 S47 −177.702 Variable S48−106.846 −1.600 S-LAH55 S49 21.S76 6.448 S50 −27.697 6.650 S-LAM66 S517367.260 0.829 S52 −129.249 5.126 S-TIH53 S53 −46.358 Variable S54538.505 −1.500 S-LAM66 S55 95.344 −11.395 S-PHM53 S56 −60.650 VariableS57 87.009 5.185 S-FSL5 S58 −165.647 −1.434 S59 −85.357 −1.500 S-TIH6S60 −1236.715 0.100 S61 50.067 7.563 S-LAL14 S62 539.692 −18.000 S63Infinity −13.537 S-BSL7 S64 Infinity 2.051 S65 Infinity 33.841 BAF52 S66Infinity Variable IMAGE Infinity Note: Maximum image diameter = 11.0 mm*Surface profiles of aspheric surfaces S12 and S26 are governed by thefollowing conventional equation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor The coefficients for the surface S12 are: the surface S26 are: K =0.01925737 K = −0.5574845 A = −1.3531387e−007 A = −1.0833227e−006 B =−1.5274225e−011 B = −9.1904879e−011 C = −2.0209982e−014 C =−1.4775967e−013 D = 5.4753514e−0i8 D = 6.5701323e−016 #Surface profileof binary surface S3 is governed by the following conventional equation:Added Phase = A₁p² + A₂p⁴ + A₃p⁶ + A₄p⁸ + A₅p¹⁰ where: A1, A2, A3, A4and A5 are coefficients and p is the normalized radial coordinate at thesurface. The normalizing factor is set at unity and the p's becomesimply radial coordinates. A1 = −0.14123699 A2 = −8.7028052e−007 A3 =−1.2255122e−010 A4 = 5.9987370e−015 A5 = −1.2234791e−019 VARIABLETHICKNESS POSITIONS AND DATA P1 P2 P3 P4 P5 P6 P7 EFL 7.264 −12.11735.980 81.979 −145.198 729.922 2100.036 F/No. −1.450 −1.450 −1.450−1.450 −1.450 9.400 −14.100 S10 3.154 50.878 −126.861 −163.460 −167.963−167.403 168.654 S17 271.009 213.056 −113.646 61.255 −10.607 68.8283.277 S24 2.350 −12.345 35.982 51.876 97.922 40.276 −104.616 S47 4.6325.482 4.658 5.264 6.015 53.226 73.878 S53 −105.364 −104.868 −105.482−104.798 −103.775 −14.725 2.050 S56 −1.550 −1.550 −1.550 −1.550 −1.55043.752 35.462 S66 4.969 4.799 4.853 4.815 5.202 4.818 5.114The prescription of binary surface 3 is included following the lenssystem optical prescription table listed above. The binary surface 3adds phase to the wavefront. By providing binary surface 3, the secondthrough fifth lens elements 2, 3, 4 and 5 in the focus portion of thelens can be made from relatively inexpensive glass, such as BK7, ratherthan expensive optical glass having abnormal dispersion characteristics,such as SFPL 51. While it is advantageous to include this binary surface3 near the front of the lens system where the axial beam diameters arelargest, it will readily appear to those skilled in the art that thebinary (diffractive) surface may be provided elsewhere and that morethan one such surface may be provided. Other methods of aberrationcorrection may also be used advantageously. It should be noted that thisembodiment also incorporates two aspheric surfaces 12 and 26.

FIG. 63 shows the zoom lens system with the zoom groups positioned atthe longest focal length and the focus group focused at infinity.Similarly, the ray aberration graphs of FIG. 64 are at infinity focusand maximum focal length. It should be noted that the use of a binarysurface in this embodiment is a modification that may be used in any ofthe embodiments of the invention disclosed herein or future variationsof the invention.

FIGS. 65 and 66 illustrate an example of another embodiment of thepresent invention. This embodiment of the zoom lens system of thepresent invention is very similar to the embodiment of FIGS. 10-62,except that a binary (diffractive) surface is provided. Specifically,the binary surface is provided on the front surface (surface No. 6 inthe prescription) of the third lens element from the left. As describedabove with respect to FIGS. 10-62, that third lens element is the first(front) of two lens elements comprising the second focus group FG2,which is movable axially for accomplishing the focusing together withthe movable first focus group FG1 comprised of only the second lenselement. The lens system optical prescription for the embodiment ofFIGS. 65 and 66 is set forth below in the tables generally entitled“Tables for FIGS. 65 and 66.”

TABLES FOR FIGS. 65 and 66 LENS SYSTEM OPTICAL PRESCRIPTION GlassSurface Radius Thickness Name OBJECT Infinity Variable S1 Infinity50.000 S2 −617.930 5.200 S-LAM60 S3 425.207 Variable S4 −2291.780 4.900S-TIH6 S5 545.459 Variable S6# 961.467 19.482 BK7 S7 −607.161 0.730 S81355.262 12.601 BK7 S9 −1118.653 Variable S10 986.310 20.386 S-FPL51 S11−502.874 0.730 S12 343.826 21.232 S-FPL51 S13 64586.450 0.730 S14181.736 24.150 S-FPL53 S15 476.848 Variable S16 208.678 3.120 S-LAH66S17* 40.147 6.111 S18 67.136 3.150 S-LAH59 S19 56.870 14.527 S20 −98.6902.730 S-LAH66 S21 90.992 12.506 S-TIH53 S22 −174.619 Variable S23764.771 14.926 S-FPL52 S24 −66.842 0.400 S25 133.738 17.704 S-FPL51 S26−69.988 3.100 S-LAM66 S27 −1580.221 0.400 S28 65.214 9.613 S-NSL36 S29129.561 Variable STOP Infinity 8.811 S31* −36.392 2.044 S-BSM14 S32−425.016 6.131 S33 −43.308 5.233 S-TIH53 S34 −33.861 0.200 S35 47.20313.980 S-FPL51 S36 −41.565 2.400 S-LAM66 S37 −56.845 0.200 S38 −109.5331.950 S-LAH63 S39 31.532 10.159 S-FPL51 S40 −173.403 45.721 S41 47.8914.513 S-LAH53 S42 −2514.287 41.843 S43 −23.807 9.483 S-LAH59 S44 −24.61012.719 S45 61.223 3.114 S-FPL51 S46 −45.071 0.150 S47 24.918 3.242S-BSM9 S48 −516.606 Variable S49 −72.073 1.059 S-LAL54 S50 23.513 2.783S51 −18.951 0.900 S-LAH59 S52 −57.174 1.347 S53 −21.150 21.292 S-LAH60S54 −31.181 Variable S55 −138.459 4.401 S-BAL22 S56 −75.648 0.300 S57606.713 5.842 S-FPL51 S58 −96.488 0.300 559 113.288 7.382 S-FPL51 560−97.742 2.500 S-TIH6 S61 −366.723 0.300 S62 400.000 0.000 S63 38.7608.585 S-FPL52 S64 269.438 5.901 S65 115.000 0.450 S66 94.072 1.770S-LAL54 S67 35.982 7.000 S68 −90.502 2.010 S-LAL8 S69 29.972 6.150S-TIH53 S70 82.308 2.725 S71 79.000 9.670 S72 76.232 6.100 S-PHM52 S73−75.003 0.761 S74 45.420 7.170 S-FSL5 S75 −45.317 1.500 S-TIH53 S76348.342 18.544 S77 Infinity 13.200 S-BSL7 S78 Infinity 2.000 S79Infinity 33.000 BAF52 S80 Infinity 0.000 S81 Infinity 0.000 IMAGEInfinity Note: Maximum image diameter = 11.3 mm *Surface profiles ofaspheric surfaces S17 and S31 are governed by the following conventionalequation:$Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}}}$where: CURV = 1/(Radius of Surface) Y = Aperture height, measuredperpendicular to optical axis K, A, B, C, D = Coefficients Z = Positionof surface profile for a given Y value, as measured along the opticalaxis from the pole (i.e. axial vertex) of the surface. The coefficientsfor The coefficients for the surface S17 are: the surface S31 are: K =−0.3564029 K = 0.4304792 A = −8.6827410e−007 A = 9.5769727e−007 B =−2.1510889e−010 B = 1.3131850e−009 C = −6.3664850e−014 C =−1.4559220e−012 D = −3.8937870e−018 D = 3.1953640e−015 #Surface profileof binary surface S6 is governed by the following conventional equation:Added Phase =A₁p² + A₂p⁴ + A₃p⁶ + A₄p⁸ + A₅p¹⁰ where: A₁, A₂, A₃, A₄ andA₅ are coefficients and p is the normalized radial coordinate at thesurface. The normalizing factor is set at unity and the p's becomesimply radial coordinates. A1 = −0.038094023 A2 = −2.7327913e−006 A3 =5.0795942e−010 A4 = −5.0245151e−014 A5 = 1.5103625e−018 VARIABLETHICKNESS POSITIONS AND DATA P1 P2 P3 P4 P5 P6 P7 EFL 7.428 12.28519.009 32.781 65.564 93.100 144.823 F/No. 1.949 1.949 1.949 1.949 1.9492.010 2.090 S0 Infinity 5322.630 2499.896 Infinity 5322.630 Infinity5322.630 S3 18.151 48.521 79.959 18.151 48.521 18.151 48.521 S5 6.39910.135 15.000 6.399 10.135 6.399 10.135 S9 71.409 37.303 1.000 71.40937.303 71.409 37.303 S15 1.350 67.051 110.745 155.094 189.151 203.856210.392 S22 319.660 247.857 197.854 142.790 92.653 65.474 50.046 S299.625 15.727 22.036 32.751 48.830 61.304 70.197 S48 1.498 1.498 1.4981.498 1.498 2.823 4.711 S54 63.257 63.257 63.257 63.257 63.257 61.93360.044 VARIABLE THICKNESS POSITIONS AND DATA P8 P9 P10 P11 P12 P13 EFL206.030 486.383 715.335 2050.042 4776.501 1890.393 F/No. 2.360 2.8405.600 14.500 14.500 5.600 S0 Infinity 5322.630 Infinity Infinity8708.002 5322.630 S3 18.151 48.521 18.151 18.151 37.472 48.521 S5 6.39910.135 6.399 6.399 8.770 10.135 S9 71.409 37.303 71.409 71.409 49.71837.303 S15 215.814 218.878 223.339 224.980 224.980 223.339 S22 33.07424.338 10.235 1.719 1.719 10.235 S29 81.746 87.419 97.063 103.934103.934 97.063 S48 9.572 14.559 31.080 63.536 63.536 31.080 S54 55.18350.196 33.675 1.220 1.220 33.675

The prescription of binary surface 6 is included following the lenssystem optical prescription table listed above. The addition of binarysurface 6 to the basic lens system optical prescription of theembodiment of FIGS. 10-62 allows the substitution of less expensiveglass, such as BK7, for the fluor-crown glass of lens elements 3 and 4(third and fourth from the left in FIG. 65). Although other smallchanges are also made in the prescription, the zoom lens system of FIGS.65 and 66 has the same number of lens elements and the same number ofmoving groups for focusing and zoom as the embodiment of FIGS. 10-62.FIG. 65 shows the zoom lens system with the zoom groups positioned atthe longest focal length and the focus groups focused at infinity.Similarly, the ray aberration graphs of FIG. 66 are at infinity focusand the longest focal length.

FIGS. 67-70 illustrate an example of another embodiment of the presentinvention. This embodiment of the zoom lens system of the presentinvention has a zoom ratio of about 400:1. Specifically, this embodimenthas a zoom range of focal lengths of about 7.47 mm (the position shownin FIG. 67) to about 2983 mm (the position shown in FIG. 68). As withthe embodiment of FIGS. 10-62, this embodiment has three moving zoomlens groups ZG1, ZG2 and ZG3, with two of them in the front zoom lensportion and one in the rear zoom lens portion. The ray aberration graphsof FIGS. 69 and 70 are at paraxial effective focal lengths (EFL) of 7.47mm and 2983 mm, respectively, and illustrate that this embodimentperforms well, considering the extremely wide range of focal lengths andlarge zoom ratio which is similar to the performance characteristics ofthe embodiment of FIGS. 10-62. The optical diagrams of FIGS. 67 and 68and the ray aberration graphs of FIGS. 69 and 70 are shown at infinityfocus.

The lens system optical prescription of FIGS. 67-70 is set forth belowin the tables generally entitled “Tables for FIGS. 67 thru 70.” Thefollowing data in the lens system optical prescription is set forth inthe same manner and the legends have the same meanings as in thepreceding lens system optical prescriptions.

TABLES FOR FIGS. 67 thru 70 LENS SYSTEM OPTICAL PRESCRIPTION GlassSurface Radius Thickness Name OBJECT Infinity Variable S1 1018.78015.000 LAH78 S2 277.432 28.775 S3 523.118 37.500 S-FPL51 S4 −634.0221.500 S5 323.390 30.000 S-FPL51 S6# −2096.922 −0.001 S7* 177.503 27.000S-FPL51 S8 667.737 Variable S9 363.133 6.000 TAF1 S10* 84.560 23.084 S11−1731.870 4.500 TAF1 S12 117.736 21.933 S13 −68.241 4.672 TAF1 S141396.861 11.280 PBH71 S15 −123.171 Variable S16 −351.922 21.562 S-FPL51S17 −87.960 0.750 S18 670.190 25.507 LAK21 S19 −96.809 4.500 FD6 S20−253.794 18.318 S21 112.307 6.052 FCS S22 345.143 Variable STOP Infinity6.066 S24* −49.612 4.500 PSK53A S25 45.951 6.491 FD15 S26 149.306 8.138S27 −53.675 2.556 PSK53A S28 −436.714 15.264 FD8 S29 −53.001 30.067 S3096.369 40.439 S-FPL51 S31 −47.937 4.500 S-LAH75 S32 −65.887 0.018 S33314.723 4.500 S-LAH75 S34 44.980 33.625 S-FPL53 S35 −197.211 62.647 S36*59.624 15.000 S-FPL53 S37 −45862.250 62.567 S38 Infinity 2.000 S39−250.000 2.000 S-LAH66 S40 38.600 21.997 S41 −42.668 3.012 PBH23W S4278.619 20.849 S-LAL8 S43 −54.572 0.250 S44 701.714 11.340 S-LAL8 S45−96.232 0.250 S46 153.694 14.173 S-LAL8 S47 −120.652 0.250 S48 57.76424.753 S-LAM2 S49 −654.450 3.706 P8H6W S50 36.175 17.533 S51 126.5172.500 PBH53W S52 123.911 5.000 S-BSM14 S53 −269.378 0.200 S54 119.3175.000 S-BSM18 S55 249.395 Variable S56 77.473 2.500 S-LAH60 S57 24.7958.736 S58 −17.880 2.000 S-LAH55 S59 −73.667 1.561 S60 −68.965 7.000PBH53W S61 −23.620 0.200 S62 −39.257 2.000 S-LAH65 S63 −73.267 VariableS64* 40.900 24.089 S-BAL42 S65* −82.736 0.200 S66 68.814 3.000 PBH53WS67 33.834 Variable S68 47.963 12.055 S-BSL7 S69 −38.097 8.000 PBH6W S70−61.203 Variable S71 Infinity 11.874 S-BSL7 S72 Infinity 14.000 IMAGEInfinity Note: Maximum image diameter = 11.0 mm *Surface profiles ofaspheric surfaces S7, S10, S24, S36, S64 and S65 are governed by thefollowing conventional equation $\begin{matrix}{Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} + {(D)Y^{10}} +}} \\{(E)Y^{12}}\end{matrix}\quad$ where: CURV = 1/(Radius of Surface) Y = Apertureheight, measured perpendicular to optical axis K, A, B, C, D, E =Coefficients Z = Position of surface profile for a given Y value, asmeasured along the optical axis from the pole (i.e. axial vertex) of thesurface. The coefficients for The coefficients for the surface S7 are:the surface S10 are: K = −0.01834396 K = 0.1385814 A = 4.6192051e−009 A= −6.1078514e−008 B = 2.9277175e−013 B = −1.7110958e−012 C =−5.3760139e−018 C = −1.4298682e−015 D = 4.4429222e−022 D =−7.3308393e−019 E = 0 E = 0 The coefficients for The coefficients forthe surface S24 are: the surface S36 are: K = −0.1283323 K = 0.009973727A = −2.7157663e−007 A = 3.3999271e−008 B = 1.4568941e−010 B =1.4717268e−010 C = −1.4055959e−012 C = −1.0665963e−013 D =9.7130719e−016 D = 6.8463872e−017 E = 0 E = 0 The coefficients for Thecoefficients for the surface S7 are: the surface S10 are: K = −4.594951K = −0.2743554 A = 5.9382510e−006 A = 1.2036084e−006 B = −4.3333569e−009B = 3.8383867e−009 C = −2.6412286e−013 C = −1.5101902e−011 D =5.0607811e−015 D = 2.3291313e−014 E = −3.8443669e−018 E =−1.3549754e−017 #Surface profile of binary surface S6 is governed by thefollowing conventional equation: Added Phase = A₁p² + A₂p⁴ + A₃p⁶ +A₄p⁸ + A₅p¹⁰ + A₆p¹² where: A₁, A₂, A₃, A₄, A₅ and A₆ are coefficientsand p is the normalized radial coordinate at the surface. Thenormalizing factor is set at unity and the p's become simply radialcoordinates. A1 = −0.0183497 A2 = 0.1385814 A3 = −0.1283323 A4 =0.0099737 A5 = −4.5949510 A6 = −0.2743554 VARIABLE THICKNESS POSITIONSAND DATA P1 P2 P3 P4 P5 P6 P7 EFL 7.471 11.746 18.475 29.059 45.676649.701 2981.989 F/No. 1.600 1.600 1.600 1.600 1.600 6.000 18.000 S0Infinity Infinity Infinity Infinity Infinity Infinity Infinity S8 3.88447.335 81.309 107.642 127.477 147.901 156.198 S15 243.496 190.547145.303 105.453 68.586 39.080 0.104 S22 5.292 14.777 26.064 39.60056.513 65.772 96.339 S55 1.000 1.000 1.000 1.000 1.000 98.702 111.239S63 117.540 117.540 117.540 117.540 117.540 30.129 0.368 S67 42.17542.175 42.175 42.175 42.175 20.670 63.421 S70 14.512 14.512 14.51214.512 14.512 25.727 0.199

Detailed Description of Folded Lens Embodiment

FIG. 71 is an optical diagram illustrating an example of still anotherembodiment of the present invention incorporating one or more mirrorsfor folding the lens for added compactness. The example of FIG. 71 issimilar to the previously-described embodiments, with three general zoomgroups identified as 50, 52 and 54. An intermediate image is located at56. The focus group 66 is movable during focusing, but is stationarywhen the lens is at a constant focus. The aperture stop is located at84. Unique to the folded zoom lens embodiment of FIG. 71 is a mirror 64located between the front and rear zoom groups 52 and 54 for “folding”or bending the radiation rays. The embodiment of FIG. 71 may be employedin any camera, but is particularly suited for small cameras such aspoint-and-shoot handheld cameras because the folded design enables thelens to fit into a smaller space. FIG. 71 illustrates an SLR embodimentcontaining a reflex mirror 60 and an eyelens 62 for enabling a user tosee the image while the reflex mirror 60 is in the position indicated inFIG. 71.

Embodiments of the present invention are particularly suited to foldingbecause mirror 64 may be placed within the intermediate image space 58in any area that does not interfere with the movement of the zoom groups52 and 54. In contrast, conventional compact zoom lenses have lenselements that must retract into the body of the camera, which eliminatesmost or all or the air gaps within the lens and precludes the insertionof a mirror. In the example of FIG. 71, the mirror 64 is located on theimage side of the intermediate image 56. However, in other embodiments,the mirror 64 may be located on the object side of the intermediateimage 56. It should be understood that other embodiments of the presentinvention may have multiple folds (mirrors), and that the mirrors needhot be oriented at 45 degrees with respect to the optical axis.

The folded lens illustrated in the example of FIG. 71 enables severaluseful design possibilities and advantages. As mentioned above, the foldin the lens enables the zoom lens to take up less space. Furthermore,the folded zoom lens enables some or all of the lens elements to residewithin the body of the camera, further improving compactness. In oneembodiment, even the focus lens group 66 may reside entirely within thebody of the camera, protecting the lens and making the camera even morecompact. In addition, the folded zoom lens enables compact cameras toachieve a zoom ratio of about 10:1 or higher, compared to a maximum ofabout 4:1 in conventional compact cameras. Moreover, conventional SLRcameras require a bulky pentaprism for flipping the image, and thuscompact cameras typically avoid through-the-lens viewing. However,because of the intermediate image 56 and mirrors 64 and 60 in thepresent invention, the final image is already properly oriented withoutthe need for a bulky pentaprism, and through-the-lens viewing is madepossible even in cameras of a compact size.

The exemplary folded zoom lens of FIG. 71 provides an EFL of about 12 mmto 120 mm, a zoom ratio of about 10:1, an “f” number range of about f/3to f/5 at full aperture and a maximum field of view angle in objectspace of about 84.1 degrees to 10.3 degrees, and receives radiationwithin a waveband of at least 486 nm to 588 nm. The image generated bythe embodiment of FIG. 71 is about 12 mm in height by about 18 mm inwidth with a diagonal dimension of about 21.65 mm, which is about halfthe size of the image in a conventional 35 mm still photography camera.

FIGS. 72A-72D are optical diagrams illustrating the folded zoom lensexample embodiment of FIG. 71 at other zoom positions, with the foldedlens shown in a flat (unfolded) orientation for clarity and the zoomgroups in various exemplary positions. As in FIG. 71, the focus lensgroup 66 in the example of FIGS. 72A-72D is movable for focusing andstationary at a constant focus, and the mirror 64 and eyelens 62 arealso stationary. The aperture stop is located at 84 and is movableduring zooming. The zoom lens example of FIGS. 72A-72D is actuallycomprised of eight moving zoom groups 68, 70, 72, 74, 76, 78, 80 and 82,although it should be understood that other embodiments of the foldedzoom lens may include more or fewer zoom groups. The folded zoom lensexample of FIGS. 72A-72D utilizes all spherical surfaces, but it shouldbe understood that other embodiments may employ aspheres and/or binary(diffractive) surfaces.

Detailed Description of Infrared Embodiment

FIGS. 73A-73C are optical diagrams for an example of an infrared (IR)embodiment of the zoom lens system of the present invention,illustrating various positions of the zoom groups. The intermediateimage is located at 86. The focus group 88 is movable during focusing,but is stationary at a constant focus. The final image plane is locatedat 90, and the aperture stop is located at 92. The embodiment of FIGS.73A-73C may be employed in low light and surveillance cameras becausethe zoom lens system is designed for infrared wavelengths. The exampleof FIGS. 73A-73C provides an EFL of 6.68 mm to 1201.2 mm, an “f” numberrange of f/2.00 to f/5.84, an image diagonal of 8.0 mm, a maximum fieldof view angle in object space of 64.5 degrees to 0.388 degrees, and avertex length of 902.28 mm. There is a −4.93% distortion at the 6.68 mmfocal length position and +0.34% distortion at the 1201.2 mm focallength position. This distortion increases the effective zoom ratio to190:1. There are a total of nine elements in the example of FIGS.73A-73C, with six elements (94, 96, 98, 100, 102 and 104) in the zoomkernel 106, and three elements (108, 110 and 112) in the zoom relay 114.Note that the “zoom kernel,” as referred to herein, represents all ofthe elements from object space to the intermediate image, while the“zoom relay,” as referred to herein, represents all of the elements fromthe intermediate image to the final image.

The lens system optical prescription for the IR embodiment of FIGS.73A-73C is set forth below in the tables generally entitled “Tables forFIGS. 73A, 73B and 73C.” The following data in the lens system opticalprescription is set forth in the same manner and the legends have thesame meanings as in the preceding lens system optical prescriptions.

TABLES FOR FIGS. 73A, 73B and 73C LENS SYSTEM OPTICAL PRESCRIPTIONRefractive Surface Radius Thickness Material OBJECT Infinity Infinity S1Infinity 25.000 S2* 341.091 15.000 GERMANIUM S3# 442.256 14.496 S4628.089 15.000 ZNSE S5 817.176 Variable S6* 191.321 5.000 GERMANIUM S7101.374 Variable S8 −108.986 5.000 GERMANIUM S9 −133.542 Variable S10*132.195 10.000 GERMANIUM S11 215.451 106.451 S12* 44.406 7.000 GERMANIUMS13* 47.364 Variable S14* −146.583 5.000 GERMANIUM S15* −103.306Variable S16* −48.015 6.000 ZNSE S17* −54.690 Variable S18* −134.5105.000 GERMANIUM S19* −96.541 Variable STOP Infinity 74.251 IMAGEInfinity Note: Maximum image diameter = 8.0 mm *Surface profiles ofaspheric surfaces S2, S6, S10, S12, S13, S14, S15, S16, S17, S18 and S19are governed by the following conventional equation: $\begin{matrix}{Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} +}} \\{{(D)Y^{10}} + {(E)Y^{12}} + {(F)Y^{14}} + {(G)Y^{16}}}\end{matrix}\quad$ where: CURV = 1/(Radius of Surface) Y = Apertureheight, measured perpendicular to optical axis A, B, C, D, E, F, G =Coefficients Z = Position of surface profile for a given V value, asmeasured along the optical axis from the pole (i.e. axial vertex) of thesurface. The coefficients for the The coefficients for the surface S2are: surface S6 are: K = −0.3170663 K = 0.0000000 A = 7.1675212e−010 A =8.8834511e−009 B = 4.6490286e−015 B = −1.1017434e−012 C = 3.1509558e−020C = 4.2407818e−016 D = −3.0230207e−026 D = −4.5843672e−020 E =1.8711604e−043 E = 0 F = 7.2023035e−034 F = 0 G = −1.6899714e−038 G = 0The coefficients for the The coefficients for the surface S10 are:surface S12 are: K = 0.0000000 K = 0.1424633 A = −4.1468720e−008 A =−1.3741884e−008 B = −1.1864804e−012 B = 2.0574529e−010 C =1.0375271e−016 C = 2.2356569e−013 D = 1.4819552e−020 D = −9.2592205e−016E = 0 E = 0 F = 0 F = 0 G = 0 G = 0 The coefficients for the Thecoefficients for the surface S13 are: surface S14 are: K = 0.1341907 K =0.0000000 A = 2.5853953e−007 A = −2.3627230e−006 B = 6.3040925e−010 B =−3.2069853e−009 C = −8.9182471e−013 C = 1.9995538e−012 D =−2.1087914e−016 D = −4.1873811e−015 E = 0 E = −4.5598387e−018 F = 0 F =1.5355757e−021 G = 0 G = 2.7742963e−025 The coefficients for the Thecoefficients for the surface S15 are: surface S16 are: K = 0.0000000 K =0.0000000 A = −1.9992749e−006 A = −5.5264489e−007 B = −2.7451965e−009 B= −3.4855834e−011 C = 2.5915567e−012 C = −1.5605019e−013 D =−5.4747396e−015 D = 8.4346229e−016 E = 1.0432409e−018 E =−2.6930213e−019 F = −9.7041838e−023 F = 7.0886850e−022 G =3.5844261e−025 G = −4.8763355e−025 The coefficients for the Thecoefficients for the surface S17 are: surface S18 are: K = 0.0000000 K =0.0000000 A = −1.9256081e−007 A = 4.5197079e−007 B = 9.7560057e−012 B =−4.7688707e−010 C = −3.1406997e−013 C = −2.2771179e−013 D =−4.6996712e−016 D = −7.3812375e−016 E = 4.3471337e−019 E =6.1621050e−019 F = −3.7957715e−022 F = −2.9782920e−023 G =−2.4875152e−026 G = −2.8295343e−026 The coefficients for the surface S19are: K = 0.0000000 A = 3.9066750e−007 B = −2.6768710e−010 C =−3.7378469e−013 D = −4.0450877e−016 E = 3.9230103e−019 F =−3.7514135e−023 G = −8.0738327e−027 #Surface profile of binary surfaceS3 is governed by the following conventional equation: Added Phase =A₁p² + A₂p⁴ + A₃p⁶ + A₄p⁸ + A₅p¹⁰ where: A₁, A₂, A₃, A₄ and A₅ arecoefficients and p is the normalized radial coordinate at the surface.The normalizing factor is set at unity and the p's become simply radialcoordinates. A1 = −0.0085882326 A2 = −1.2587653e−008 A3 =−5.4668365e−013 A4 = 8.4183658e−018 A5 = 1.3774055e−022 VARIABLETHICKNESS POSITIONS AND DATA P1 P2 P3 P4 P5 P6 EFL 6.677 7.583 9.33111.805 14.069 23.805 F/No. 2.000 2.000 2.000 2.000 2.000 2.000 S5 5.00025.000 55.000 85.000 105.000 155.000 S7 239.848 216.543 180.384 143.845119.259 58.715 S9 72.916 76.220 82.379 88.919 93.504 104.048 S13 276.674276.674 276.674 276.674 276.674 276.674 S15 5.030 5.030 5.030 5.0305.030 5.030 S17 29.517 29.517 29.517 29.517 29.517 29.517 S19 5.0005.000 5.000 5.000 5.000 5.000 VARIABLE THICKNESS POSITIONS AND DATA P7P8 P9 P10 P11 P12 EFL 48.419 84.275 133.455 175.637 231.172 304.215F/No. 2.000 2.000 2.000 2.300 2.900 3.400 S5 205.000 231.305 243.545243.545 243.545 243.545 S7 16.543 30.757 72.218 72.218 72.218 72.218 S996.221 55.701 2.000 2.000 2.000 2.000 S13 276.674 276.674 276.674248.444 220.313 187.659 S15 5.030 5.030 5.030 42.180 79.972 109.931 S1729.517 29.517 29.517 22.953 12.626 5.000 S19 5.000 5.000 5.000 2.6443.310 13.631 VARIABLE THICKNESS POSITIONS AND DATA P13 P14 P15 P16 P17EFL 400.368 526.915 693.449 912.675 1201.182 F/No. 3.500 3.800 4.6005.300 5.840 S5 243.545 243.545 243.545 243.545 243.545 S7 72.218 72.21872.218 72.218 72.218 S9 2.000 2.000 2.000 2.000 2.000 S13 146.432112.380 97.552 94.304 95.940 S15 114.831 95.642 67.311 40.305 16.014 S1710.137 19.763 26.212 25.615 18.454 S19 44.821 88.436 125.146 155.997185.814

FIGS. 74-76 are ray aberration graphs corresponding to the position ofthe zoom groups shown in FIGS. 73A-73C, respectively. The ray aberrationgraphs of FIGS. 74-76 are at paraxial effective focal lengths (EFL) of6.68 mm, 133.46 mm, and 1201.18 mm, respectively, and a wavelength rangeof 8-12 microns. The optical diagrams of FIGS. 73A-73C and the rayaberration graphs of FIGS. 74-76 are shown at infinity focus.

Detailed Description of 3-5 Micron Infrared Embodiment

FIG. 77 illustrates an unfolded layout of a second exemplary IRembodiment of the zoom lens system with lens elements and surfacesidentified. Referring to FIG. 77, each lens element is identified by anumeral from 120 through 138 (by twos) and the general configuration ofeach lens element is depicted, but the actual radius of each lenssurface is set forth below in the table entitled “TABLE FOR FIGS. 77 AND78A-78F.” The lens surfaces are identified by the letter “S” followed bya numeral from S0 through S23. The optical axis is identified by thesymbol “Ø”. Each lens element has its opposite surfaces identified by aseparate but consecutive surface number as, for example, lens element120 has lens surfaces S1 and S2, lens element 126 has lens surfaces S7and S8 and so forth. The intermediate image is located between S10 andS12. An optical stop is located at S22. The real image surface isidentified by the numeral S23. All of the lens surfaces are sphericalexcept lens surfaces S2, S8, S9 and S21 which are aspheric surfaces thatare non-spherical, non-plano but rotationally symmetrical about theoptical axis.

There are a total of 10 elements in the example of FIG. 77, with fiveelements (120, 122, 124, 126 and 128) in the zoom kernel or first lensgroup 151, and five elements (130, 132, 134, 136 and 138) in the zoomrelay or second lens group 156. The optical design of the secondexemplary IR embodiment can be characterized as an NPP kernel followedby an NNP relay. Note that the “zoom kernel,” as referred to herein,represents all of the elements from object space to the intermediateimage, while the “zoom relay,” as referred to herein, represents all ofthe elements from the intermediate image to the final image.

The light rays entering the zoom lens system at the left are comprisedof exemplary axial field beams 160 and exemplary off-axis field beams162, 164 and 166, with the outer light rays in each field beam referredto as rim rays and the inner light ray in each field beam referred to asa chief or principal light ray. The off-axis field beam whose rim ray isfurthest from the optical axis is referred to as the off-axis field beammaximum rim ray. Note that the off-axis field beam chief ray firstcrosses the optical axis before the intermediate image, and latercrosses the optical axis again at the optical stop.

Before describing the detailed characteristics of the lens elements, abroad description of the lens groups and their axial positions andmovement will be given for the zoom lens system, generally designated150, of this second exemplary embodiment of the present invention.Beginning from the end facing the object to be photographed, i.e. theleft end in FIG. 77, the first lens group 151 comprises a first lenssubgroup 152, a first zoom subgroup 153, a second zoom subgroup 154, anda third zoom subgroup 155. The first lens subgroup 152 is apositive-powered subgroup and comprises singlet lens element 120 whichgathers light from object space. The first lens subgroup 152 is movableduring focusing, but is stationary and at a fixed distance with respectto the image plane S23 at a constant focus. The first zoom subgroup 153is a negative-powered subgroup and comprises singlet lens elements 122and 124. The second zoom subgroup 154 is a positive-powered subgroup andcomprises a singlet lens element 126. The third zoom subgroup 155 is apositive-powered subgroup and comprises a singlet lens element 128. Asecond lens group 156 comprises a fourth zoom subgroup 157, a fifth zoomsubgroup 0.158, and a sixth zoom subgroup 159. The fourth zoom subgroup157 is a negative-powered subgroup and comprises a singlet lens element130. The fifth zoom subgroup 158 is a negative-powered subgroup andcomprises a singlet lens element 132. The sixth zoom subgroup 159 is apositive-powered subgroup and comprises singlet lens elements 134, 136and 138, and includes an optical stop at S22. Although element 138 inthe sixth zoom subgroup is rather thin in the example provided, inalternative embodiments this element may be thickened to improve itsmanufacturability. An axially movable intermediate image is locatedbetween the third zoom subgroup 155 and the fourth zoom subgroup 157.The second exemplary IR embodiment of the zoom lens system is set forthbelow in the table entitled “TABLE FOR FIGS. 77 AND 78A-78F.”

There are six independently moving groups altogether, three on theobject side and three on the image side of the intermediate image. Thehorizontal arrows with arrowheads on both ends in the upper portion ofFIG. 77 indicate that each of the zoom subgroups 153-159 are movable inboth axial directions along the optical axis, some in a monotonic manner(i.e. in only one direction when progressing from one extreme to theother of adjustments) and others in a non-monotonic manner. While onlythe lens elements are physically shown in FIG. 77, it is to beunderstood that conventional mechanical devices and mechanisms areprovided for supporting the lens elements and for causing axial movementof the movable groups in a conventional lens housing or barrel.

Note that the space between lens elements as shown in FIG. 77 and FIGS.78A-78F suggests that a fold mirror could be located between zoomsubgroups 154 and 155 and/or between the optical stop at S22 and thefinal image at S23 to create a folded embodiment.

The embodiment of FIG. 77 may be employed in low light and surveillancecameras because the zoom lens system is designed for IR wavelengths. Theexample of FIG. 77 provides an EFL of about 11.8 mm to 1137.1 mm, an “f”number range of about f/2.80 to f/4.00, an image diagonal of about 18.0mm, a maximum field of view angle in object space of about 0.45 degreesto 37.36 degrees, and a vertex length from the front vertex (i.e.surface S1) to the final image (i.e. surface S22) of about 945 mm. Thereis a 1.55% distortion at the 11.8 mm focal length position and 2.14%distortion at the 1137.1 mm focal length position. This distortionincreases the effective zoom ratio to approach about 100:1.

FIGS. 78A-78F are optical diagrams for the second exemplary IRembodiment of the zoom lens system, illustrating various positions ofthe zoom groups. It should be noted that lens elements 120 and 122 (theleftmost two elements) in FIG. 78A, although apparently touching, are infact separated by a gap. Note also that in FIG. 78F, all rim rays forboth the axial field beam and the off-axis field beams are roughlysuperimposed on each other, which enables the front lens element 120 tobe made smaller and cheaper. In particular, the off-axis field beammaximum rim ray height (distance from rim ray to optical axis) is about158.82 mm, and the axial field beam rim ray height is about 149.53 mm.The ratio of the off-axis field beam maximum rim ray distance to theaxial field beam rim ray distance is about 1.062, which indicates thatthe first lens subgroup elements had to be made larger than ideal byonly about 6.2%. It should be understood that a ratio of less than 1.25is generally acceptable. Ideally, the off-axis field beam maximum rimrays and the axial field beam rim rays would be exactly superimposed oneach other, resulting in a ratio of 1.000 and optimal size and cost forat least the first lens group.

The lens system optical prescription and fabrication data for the secondexemplary IR embodiment of FIGS. 77 and 78A-78F is set forth below inthe table generally entitled “TABLE FOR FIGS. 77 AND 78A-78F.” In theTABLE FOR FIGS. 78A-78F, the first column “ITEM” identifies each opticalelement, with the same numeral or label as used in FIG. 77. The secondand third columns identify the “Group” and “Subgroup,” respectively, towhich that optical element (lens) belongs with the same numerals used inFIG. 77. The fourth column “Surface” is a list of the surface numbers,of the object S0, the Stop (iris) S22, the image plane S23 and each ofthe actual surfaces of the lenses, as identified in FIG. 77. The fifthcolumn “Zoom Position” identifies six typical zoom positions (Z1-Z6) ofthe zoom subgroups 153-159 (illustrated in FIGS. 78A-78F) wherein thereare changes in the distance (separation) between some of the surfaceslisted in the fourth column, as described below more thoroughly. Thesixth column, headed by the legend “Radius of Curvature,” is a list ofthe optical surface radius of curvature for each surface, with a minussign (−) meaning the center of the radius of curvature is to the left ofthe surface, as viewed in FIG. 77, and “Infinity” meaning an opticallyflat surface. The asterisk (*) for surfaces S2, S8, S9 and S21 indicatethese are aspheric surfaces for which the “radius of curvature” is abase radius, and the formula and coefficients for those two surfaces areset forth as a footnote to the TABLE FOR FIGS. 77 AND 78A-78F at the *(asterisk). The seventh column “Thickness or Separation” is the axialdistance between that surface (fourth column) and the next surface. Forexample, the distance between surface S3 and surface S4 is 9.0 mm.

The eighth column of the TABLE FOR FIGS. 77 AND 78A-78F provide therefractive material of each lens element. The last column of the TABLEFOR FIGS. 77 AND 78A-78F headed “Aperture Diameter” provides the maximumdiameter for each surface through which the light rays pass. All of themaximum aperture diameters, except for the Stop surface S22, arecalculated assuming an image diagonal of 18 mm and a relative apertureranging from f/2.8 at the shortest focal length to f/4.0 at the longestfocal length. The maximum aperture diameters of the Stop surface S22 forZoom Positions Z1-Z6 are 30.170 mm, 29.727 mm, 28.999 mm, 28.286 mm,25.654 mm and 21.076 mm, respectively. The maximum relative apertures(f-number) for Zoom Positions Z1-Z6 are f/2.80, f/2.86, f/2.93, f/3.00,f/3.30 and f/4.00, respectively. Depending on the choice of the value ofthe maximum relative apertures for Zoom Positions Z1-Z6, then in one ormore zoom positions a very small negative air gap may occur at the edgesof certain elements between zoom subgroups. Those skilled in the artwill realize that the small negative air gap can be removed from thesystem by routine optimization without changing the basic design.

TABLE FOR FIGS. 77 AND 78A-78F OPTICAL PRESCRIPTION Radius of Thicknessor Aperture Sub- Zoom Curvature Separation Refractive Diameter ItemGroup Group Surface Position (mm) (mm) Material (mm) S0 (Object)Infinity 25.000 120 151 152 S1 All 215.343 28.544 Silicon 317.642 S2 Z1269.106* 9.864 308.262 Z2 57.468 Z3 108.517 Z4 117.957 Z5 132.937 Z6135.615 122 151 153 S3 All 637.888 9.000 Germanium 187.169 S4 All247.226 11.642 174.123 124 151 153 S5 All 228.929 8.000 Silicon 166.617S6 Z1 161.278 244.587 157.148 Z2 220.842 Z3 150.487 Z4 74.335 Z5 22.911Z6 11.974 126 151 154 S7 All 288.682 15.448 Silicon 176.490 S8 Z11321.765* 212.856 174.473 Z2 233.828 Z3 270.854 Z4 362.883 Z5 443.606 Z6460.309 128 151 155 S9 All 83.756* 11.053 Silicon 105.651 S10 Z1 159.357160.888 103.666 Z2 115.791 Z3 97.933 Z4 72.886 Z5 28.278 Z6 20.171 S11(dummy) Z1 Infinity 74.210 Z2 46.803 Z3 3.191 Z4 3.253 Z5 57.219 Z619.714 130 156 157 S12 All −32.997 12.500 Silicon 29.867 S13 Z1 −45.3081.830 36.698 Z2 29.317 Z3 74.625 Z4 73.197 Z5 0.800 Z6 1.897 132 156 158S14 All −28.877 10.206 Germanium 23.882 S15 Z1 −44.286 1.917 30.694 Z20.995 Z3 0.100 Z4 0.926 Z5 4.846 Z6 18.907 134 156 159 S16 All 6208.24413.998 Germanium 37.741 S17 All 264.338 0.400 40.076 136 S18 All 171.85511.452 Silicon 41.269 S19 All −84.226 0.400 42.354 138 S20 All −128.6851.000 Silicon 41.072 S21 Z1 −156.416* 1.254 41.075 Z2 1.696 Z3 0.750 Z41.699 Z5 15.734 Z6 38.441 S22 (Stop) All Infinity 79.221 S23 (Image) AllInfinity 0.000 *Surface profiles of aspheric surfaces S2, S8, S9 and S21are governed by the following conventional equation: $\begin{matrix}{Z = {\frac{({CURV})Y^{2}}{1 + \left( {1 - {\left( {1 + K} \right)({CURV})^{2}Y^{2}}} \right)^{1/2}} + {(A)Y^{4}} + {B(Y)}^{6} + {(C)Y^{8}} +}} \\{{(D)Y^{10}} + {(E)Y^{12}} + {(F)Y^{14}}}\end{matrix}\quad$ where: CURV = 1/(Radius of Curvature) Y = Apertureheight, measured perpendicular to optical axis K, A, B, C, D, E, F =Coefficients Z = Position of surface profile for a given Y value, asmeasured along the optical axis from the pole (i.e. axial vertex) of thesurface. The coefficients for the surface S2 of item 1 are: Thecoefficients for the surface S9 of item 5 are: K = −0.23909 K =−0.321348 A = −1.20061E−09 A = −1.84849E−07 B = 7.10421E−15 B =−3.24508E−11 C = −6.54538E−21 C = 4.30816E−14 D = 1.74055E−26 D =−2.13370E−18 E = 2.64213E−29 E = −7.80714E−21 F = −1.38143E−33 F =1.67339E−24 The coefficients for the surface S8 of item 4 are: Thecoefficients for the surface S21 of item 10 are: K = 28.74452 K =1.125040 A = 1.70772E−09 A = 8.42238E−07 B = 6.46357E−14 B = 2.42138E−11C = −6.99028E−18 C = 4.68290E−13 D = 2.65455E−21 D = 1.19515E−15 E =−4.37148E−25 E = −2.58757E−18 F = 2.27757E−29 F = 3.72479E−21

The foregoing footnote * to the TABLE FOR FIGS. 77 AND 78A-78F includesthe equation for calculating the shape of the aspheric surfaces S2, S8,S9 and S21 for the value Z, wherein CURV is the curvature at the pole ofthe surface, Y is the height or distance from the optical axis of aspecific point on the surface of the glass, K is the conic coefficient,and A, B, C, D, E and F are the 4th, 6th, 8th, 10th, 12th and 14th,respectively, order deformation coefficients. As noted above, forillustrating the scope and versatility of the present invention thereare six different Zoom Positions Z1-Z6 set forth in the data of theTABLE FOR FIGS. 77 AND 78A-78F which provide specific data for sixdifferent positions for the six movable zoom subgroups. The ZoomPositions Z1-Z6 are representative of six positions of the zoomsubgroups 153-159 with Zoom Positions Z1 and Z6 being the extremepositions and Z2, Z3, Z4 and Z5 being intermediate positions. Of course,it will be understood that continuous zooming is available between theextreme Zoom Positions Z1 and Z6, and that any combination of continuouszooming is available within the described zoom ranges with the lenssystem 150. In addition, continuous focusing is available over the fullrange of axial motion of the first lens group 152.

The Effective Focal Length (EFL), Full Field Of View (FFOV) and F-numberof the lens system 150 varies for the different Zoom Positions.Referring again to FIGS. 78A-78F, the zoom lens system 150 is shown withthe zoom groups in various Zoom Positions and with light ray traces forthose positions. FIG. 78A represents the zoom position Z1 for which datais set forth above in the TABLE FOR FIGS. 77 AND 78A-78F with an EFL ofabout 11.787 mm, a FFOV of about 74.72°, and an F-number of about 2.8.FIG. 78B represents the zoom position Z2 from the TABLE FOR FIGS. 77 AND78A-78F with an EFL of about 22.999 mm, a FFOV of about 42.74°, and anF-number of about 2.9. FIG. 78C represents the zoom position Z3 from theTABLE FOR FIGS. 77 AND 78A-78F with an EFL of about 54.974 mm, a FFOV ofabout 18.6°, and an F-number of about 2.9. FIG. 78D represents the zoomposition Z4 from the TABLE FOR FIGS. 77 AND 78A-78F with an EFL of about125.359 mm, a FFOV of about 8.22°, and an F-number of about 3.0. FIG.78E represents the zoom position Z5 from the TABLE FOR FIGS. 77 AND78A-78F with an EFL of about 359.536 mm, a FFOV of about 2.86°, and anF-number of about 3.3. FIG. 78F represents the zoom position Z6 from theTABLE FOR FIGS. 77 AND 78A-78F with an EFL of about 1137.054 mm, a FFOVof about 0.9°, and an F-number of about 4.0.

From the specifications for the individual lens elements (items 120-138by twos) and the separation between lens elements set forth in the TABLEFOR FIGS. 77 AND 78A-78F, the focal lengths of each lens element andthen each group of lens elements (i.e. first lens group 152, first zoomsubgroup 153, second zoom subgroup 154, third zoom subgroup 155, fourthzoom subgroup 157, fifth zoom subgroup 158, and sixth zoom subgroup 159)may be calculated by using CODE V® optical design software that iscommercially available from Optical Research Associates, Inc., Pasadena,Calif., U.S.A., at a temperature of 20° C. (68° F.) and standardatmospheric pressure (760 mm Hg), and those calculated group focallengths are as follows:

-   -   First lens subgroup 152 (element 120)=322.994 mm;    -   First zoom subgroup 153 (elements 122 and 124)=−88.338 mm;    -   Second zoom subgroup 154 (element 126)=150.688 mm;    -   Third zoom subgroup 155 (element 128)=65.962 mm; and    -   Fourth zoom subgroup 157 (element 130)=−178.124 mm.    -   Fifth zoom subgroup 158 (element 132)=−54.620 mm.    -   Sixth zoom subgroup 159 (elements 134, 136 and 138)=35.153 mm.

As mentioned above, the zoom lens system 150 is provided with oneoptical stop at the surface S22 which controls the diameter of theaperture through which light rays may pass at that point to therebycause any light rays in the zoom lens system radially beyond thatdiameter to be stopped. The optical stop is the location at which aphysical iris is located. The iris is located within or at an end of thesixth zoom subgroup 159, and moves with that zoom subgroup. Note that inFIG. 78A, for example, the rim rays pass through S22 with room to spare,while in FIG. 78F, the rim rays are almost touching the extreme edges ofS22 as they pass through the optical stop. This shows that the irislocated at S22 must open as the focal length increases. To maintain aconstant f-number at the image, the iris must “zoom” or change. In otherwords, the iris must be adjusted for constant aperture. A separate cammay be used to open or close the iris during zooming. In addition, itshould be noted that all of the lens element surface apertures, setforth in the TABLE FOR FIGS. 77 AND 78A-78F, act as field stops at allfocus and zoom positions as depicted in FIGS. 78A-78F. The size of theaperture of iris S22 is adjusted as the sixth zoom subgroup 159 movesaxially, as described above, with respect to the maximum aperturediameters listed in the TABLE FOR FIGS. 77 AND 78A-78F and is given withits largest value in the TABLE FOR FIGS. 77 AND 78A-78F.

In the second exemplary IR embodiment of the zoom lens system, thesensor located at the image plane S23 is responsive not to light but tothe amount of heat given off by the objects being viewed, and capturesdifferences in the heat given off by the objects down to a MinimumResolvable Temperature Difference (MRTD). To do this, the sensoraverages the temperature of elements in the scene being viewed. Thesensor ideally should not “see” any lens structure, otherwise thetemperature of the lens structure would be averaged into the scene andcause image errors. Therefore, in embodiments of the present invention,the stop (i.e. the iris located at the stop) is part of the detector,and the detector including the stop is cooled to reduce electronicnoise, producing a “cold stop.”

The six zoom subgroups 153-159 are each axially movable independentlyand their respective movements are coordinated by any convenient means,such as conventional mechanical devices such as cams or the like, toaccomplish the desired zooming function.

FIGS. 79A-79F illustrate the diffraction modulation transfer function(MTF) for the same light rays entering the lens system at the relativefield heights shown in FIGS. 78A-78F according to embodiments of thepresent invention. In FIGS. 79A-79F, the x-axis represents the spatialfrequency (resolution) in cycles per millimeter, and the y-axisrepresents a relative modulation value (an indication of image quality).The diffraction MTF curves of FIGS. 79A-79F are polychromatic, using thesame wavelengths and X and Y field fans, but with wavelength weights.Note that at a spatial frequency of about 15 cycles/mm, at the extremeright distal end of each of the plots, the diffraction MTF for all ofthe field fans in each of the plots are clustered with a modulationrange of about 0.65 to 0.82. In general, diffraction MTFs greater than0.50 are desired, and a lens is said to be “diffraction limited” (ideal)if the diffraction MTFs are greater than 80%. Thus, there is not much ofa dropoff from the diffraction limit in the lens of the presentinvention. The maximum distortion in the six zoom positions of FIGS.79A-79F is about 3.5%.

Although the present invention has been fully described in connectionwith embodiments thereof with reference to the accompanying drawings, itis to be noted that various changes and modifications will becomeapparent to those skilled in the art. Such changes and modifications areto be understood as being included within the scope of the presentinvention as defined by the appended claims.

1. An infrared zoom lens system for forming a final image of an object,said system having an object side and an image side and forming a firstintermediate real image between the object and the final image, saidsystem comprising: a first lens group including at least two lenselements and located between the object and the first intermediate realimage, said first lens group comprising at least one zoom subgroup whichis moved to change the size (magnification) of the first intermediatereal image; a second lens group including at least two lens elements andlocated between the first intermediate real image and the final image,at least a portion of which is moved to change the size (magnification)of the final image; and an optical stop located between the intermediateimage and the final image; wherein off-axis field beam chief rays firstcross an optical axis of the infrared zoom lens system on the objectside of the intermediate image and then cross the optical axis again atthe optical stop; and wherein a ratio of a maximum off-axis field beamrim ray to an axial field beam rim ray at a lens surface of the firstlens group adjacent to object space at a longest focal length of thezoom lens system is less than about 1.25.
 2. The infrared zoom lenssystem as recited in claim 1, wherein the optical stop is locatedbetween a last element surface of the second lens group and the finalimage.
 3. The infrared zoom lens system as recited in claim 1, whereinthe infrared zoom lens system is capable of forming the final image fromreceived radiation in the range of about 3-5 microns.
 4. The infraredzoom lens system as recited in claim 1, wherein the first lens groupcomprises five lens elements and the second lens group comprises fivelens elements.
 5. The infrared zoom lens system as recited in claim 1,wherein the first lens group and the second lens group comprise a sevengroup system with one axially stationary lens subgroup and six axiallymovable zoom subgroups.
 6. The infrared zoom lens system as recited inclaim 1, wherein the first lens group comprises three zoom subgroups andthe second lens group comprises three zoom subgroups.
 7. The infraredzoom lens system as recited in claim 1, wherein the first lens groupcomprises one axially stationary lens subgroup.
 8. The infrared zoomlens system as recited in claim 1, wherein the lens elements include oneor more germanium lens elements and one or more silicon lens elements.9. The infrared zoom lens system as recited in claim 1, wherein at leastone of the lens elements includes an aspheric surface.
 10. The infraredzoom lens system as recited in claim 5, wherein the first lens groupcomprises a first lens subgroup of positive power, a first zoom subgroupof negative power, a second zoom subgroup of positive power, and a thirdzoom subgroup of positive power, and the second lens group comprises afourth zoom subgroup of negative power, a fifth zoom subgroup ofnegative power, and a sixth zoom subgroup of positive power.
 11. Aninfrared zoom lens system for forming a final image of an object, saidsystem having an object side and an image side and forming a firstintermediate real image between the object and the final image, saidsystem comprising: a first lens group including a first five lenselements and located between the object and the first intermediate realimage, said first lens group comprising at least one zoom subgroup whichis moved to change the size (magnification) of the first intermediatereal image; a second lens group including a second five lens elementsand located between the first intermediate real image and the finalimage, at least a portion of which is moved to change the size(magnification) of the final image; and an optical stop located betweenthe intermediate image and the final image; wherein off-axis field beamchief rays first cross an optical axis of the infrared zoom lens systemon the object side of the intermediate image and then cross the opticalaxis again at the optical stop; wherein a ratio of a maximum off-axisfield beam rim ray to an axial field beam rim ray at a lens surface ofthe first lens group adjacent to object space at a longest focal lengthof the zoom lens system is less than about 1.25; and wherein lenselement surfaces, a location of an object on the object side identifiedas (Object), a location of the optical stop identified as (Stop), alocation of the final image identified as (Image), radii ofcorresponding surfaces, distances from one surface to a next surface,material between a corresponding surface and the next surface, and amaximum diametric diameter of light rays passing through thecorresponding surface have the following order, relationships andcharacteristics: Radius of Thickness or Aperture Sub- Zoom CurvatureSeparation Refractive Diameter Item Group Group Surface Position (mm)(mm) Material (mm) S0 (Object) Infinity 25.000 120 151 152 S1 All215.343 28.544 Silicon 317.642 S2 Z1 269.106* 9.864 308.262 Z2 57.468 Z3108.517 Z4 117.957 Z5 132.937 Z6 135.615 122 151 153 S3 All 637.8889.000 Germanium 187.169 S4 All 247.226 11.642 174.123 124 151 153 S5 All228.929 8.000 Silicon 166.617 S6 Z1 161.278 244.587 157.148 Z2 220.842Z3 150.487 Z4 74.335 Z5 22.911 Z6 11.974 126 151 154 S7 All 288.68215.448 Silicon 176.490 S8 Z1 1321.765* 212.856 174.473 Z2 233.828 Z3270.854 Z4 362.883 Z5 443.606 Z6 460.309 128 151 155 S9 All 83.756*11.053 Silicon 105.651 S10 Z1 159.357 160.888 103.666 Z2 115.791 Z397.933 Z4 72.886 Z5 28.278 Z6 20.171 S11 (dummy) Z1 Infinity 74.210 Z246.803 Z3 3.191 Z4 3.253 Z5 57.219 Z6 19.714 130 156 157 S12 All −32.99712.500 Silicon 29.867 S13 Z1 −45.308 1.830 36.698 Z2 29.317 Z3 74.625 Z473.197 Z5 0.800 Z6 1.897 132 156 158 S14 All −28.877 10.206 Germanium23.882 S15 Z1 −44.286 1.917 30.694 Z2 0.995 Z3 0.100 Z4 0.926 Z5 4.846Z6 18.907 134 156 159 S16 All 6208.244 13.998 Germanium 37.741 S17 All264.338 0.400 40.076 136 S18 All 171.855 11.452 Silicon 41.269 S19 All−84.226 0.400 42.354 138 S20 All −128.685 1.000 Silicon 41.072 S21 Z1−156.416* 1.254 41.075 Z2 1.696 Z3 0.750 Z4 1.699 Z5 15.734 Z6 38.441S22 (Stop) All Infinity 79.221 S23 (Image) All Infinity 0.000.